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Myles Allen writes

Myles Allen has asked me to post this response to the thread in which we discussed his Communicate 2011 lecture.

I do think it is sad for democracy that so much energy in the debate on climate change has been expended on pseudo-debates about the science, leaving no room for public debate about the policy response. In the run-up to Copenhagen, public discussion of effective alternatives to a global cap-and-trade regime (which I would personally view with as much scepticism as most of the readers of this blog) was remarkably absent. It still is, and it always will be as long as the public are kept distracted by a debate over the Medieval Warm Period, which has only ever featured in one of the lines of evidence for human influence on climate (and not, in my view, a particularly strong one). The data we primarily rely upon is the instrumental temperature record, which, as I explained in the talk, emerged from the CRU e-mail affair pretty much unscathed (and I stand by the assertion that one would not have got this impression from media coverage of the issue).

My fear is that by keeping the public focussed on irrelevancies, you are excluding them from the discussion of what we should do about climate change should the decade-to-decade global warming trend observed since the 1970s continue and turn out, as current evidence suggests, to be largely caused by the increase in atmospheric greenhouse gas concentrations. Already, I find people arguing that so much has been invested in the emission cap-and-trade approach that it is too late to consider any alternative. In twenty years time, we may find people arguing that it is too late for any alternative to global geo-engineering, which seems even harder to reconcile with democracy. I believe there are effective alternatives that would represent much less of an intrusion into individual lives and the operation of the economy: for example, — but they aren't going to happen unless we start talking about them.

To be clear, "good for the planet" in the final line of the talk does not, of course, mean "good for us (or our grandchildren)". That is the whole point. I sincerely hope we do not end up in a situation where governments feel justified in taking highly anti-democratic measures to stabilise global temperatures, however effective they might be. I still believe this is a problem we can solve without compromising fundamental democratic principles, but the longer we leave off talking seriously about it, the harder this will be.

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Reader Comments (229)

The key evidence provided for the headline attribution statement "Most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations" was the comparison of model simulations forced with and without anthropogenic drivers with the instrumental temperature record.

Such a test is worthless. I could produce a model which invokes god to create life, then run that model without god, at which point life would not occur, and then declare god as the source of life. I've "proven" it with two model runs.

A second important reason that this test is inappropriate is that models fail to replicate natural variability, in particular the long term persistence that is strongly evident in both the instrumental temperature record and essentially all proxies.

If the models cannot replicate the correct, observed natural variability then they are as useful as a null hypothesis as my hypothetical god model for testing the validity of creationism. (And they do fail to capture the statistical behaviour of natural variability, e.g. as outlined in the references below)

In my own field (remote sensing) such a paper would be not be taken seriously (although perhaps accepting further work might be interesting), yet apparently it is a cornerstone of climate science.

Prof. Allen, many of those who are dismissive of your claims have considerable experience at modelling real-world phenomena and are very much aware how easy it is to have too much confidence in your own models. I sometimes refer to this as "drinking your own bath water". Which is why much of the criticism of climate science comes from hard science and engineering disciplines - these people are enormously experienced in converting modelling results into usable predictions; they know what needs to be done to make things work and also know that what you have presented to date is not sufficient to be reliable.

Refs below.

1. Anagnostopoulos, G. G., D. Koutsoyiannis, A. Christofides, A. Efstratiadis, and N. Mamassis, "A comparison of local and aggregated climate model outputs with observed data", Hydrological Sciences Journal, 55 (7), 1094–1110, 2010.

2. Koutsoyiannis, D., A. Efstratiadis, N. Mamassis, and A. Christofides, "On the credibility of climate predictions", Hydrological Sciences Journal, 53 (4), 671–684, 2008.

May 27, 2012 at 10:39 PM | Unregistered CommenterSpence_UK

Hi All,

I was in the papers last Tuesday through no initiative of my own, but because I was asked by Intel to talk to their technology ambassador who happens to be Andrew Montford then decided to dig up an unflattering image on YouTube and it was rapidly whipped up into a claim I was plotting to overthrow democracy, all without anyone taking the trouble to ask me what I meant. Since I do care about democracy a lot more than I care about the Medieval Warm Period, I tried to post to explain that my concern was that the way the climate debate was going, you were running the risk of continuing to argue about things that may ultimately turn out to be irrelevant rather than formulating sensible alternatives to some of the more anti-democratic measures that are being tossed around. For my pains, I have now been called an "idiot", "prat", "arrogant" and I don't know what else. I have also been mocked for posting on a sunny Sunday morning, and for failing to respond to posts made on a sunny Sunday afternoon.

Now, it seems, Andrew is running a caption competition. What is the problem, Andrew? I wasn't criticising your book, I was criticising journalists for giving the public the impression that the UEA e-mails called into question the integrity of the data we use for detection and attribution of human influence on climate.

I do appreciate there have been a couple of thoughtful comments on this thread, but I'm afraid I'm going to have to sign off. Many of you have remarked to me that you find mainstream climate scientists are reluctant to engage with you. If you read this thread, I think you will understand why.

Good night, everyone,


May 28, 2012 at 12:28 AM | Unregistered CommenterMyles Allen

I am extremely disappointed.

Myles Allen's response reads more like a lawyer's brief advocating his client's case than the considered thoughts of a scientist.

But that's what happens when ideological certainty replaces scientific skepticism.

May 28, 2012 at 12:35 AM | Unregistered CommenterSparkey

My original posting was in reference to the original response and not Mr. Allen's May 28, 2012 at 12:28 AM post.

However, rather thin skinned for someone who advocates so much change and sacrifice don't cha'think?

In any other field of engineering or science the behavior exposed in the UAE emails you defend would result in firings and humiliation.

"Medieval Warm Period... Medieval Warm Period..."
Great straw man argumentation, brush off just one of the hundreds of criticisms and ignore all the others by hand-waving them away as "irrelevancies". You haven't engaged, you have patronized, and you have reaped the reward of patronizing those who you don't care to understand. (And who are, by all indications, better informed than you.)

"...all without anyone taking the trouble to ask me what I meant"
In the future I suggest that you try explaining what you mean the first time. Remember, any message that can be misunderstood will be misunderstood. That miscommunication is the fault of the transmitter, not the receiver.

My criticism stands, you are a lawyer advocating your client's case not a scientist expounding on datum or theory.

May 28, 2012 at 1:05 AM | Unregistered CommenterSparkey

The divide you perceive is unfortunate, but, sadly enough a real one.

I think many were taken aback by your claim that all of Climategate amounts to a measly 0.00something degrees Celsius of correction in the global temperature record. That was the starting point.

I think, as unsavoury as it is, what has happened is a reflection of how scientists in the consensus camp, and their critics (aka the pseudo-debating sceptics) are running on parallel tracks and in opposite directions never to meet.

For instance, you say you care more about democracy than about the Medieval Warm period. Sceptics think the science of the Medieval warm period is used to shut down democracy! You see different aspects of the climate debate as watertight compartments. They are not. The MWP blends into the IPCC, and then into Climategate and so on. You come across as quite uninformed in these matters, but that is part of the reason for the response you are seeing.

I also think you shouldn't walk away with a sense that your participation was not appreciated. I, for one, can see several of the points you raised in your talk and ensuing comments. Online debate is rough, and can be time-consuming. The practitioners have gone over several of the points you raised, many times over , and are already in possession of counter-points.

May 28, 2012 at 1:06 AM | Registered Commentershub

Oh dear, 'a big boy done it' and run away tactics. It is incumbent upon those making claims about something unnatural happening to support those claims. This is how science works, well the sort of science I was taught and practice anyway. This is 'big boy' science, I suggest if one doesn't like honest 'big boy' scientific opinion one sticks to ones fave climate journals.

May 28, 2012 at 1:07 AM | Unregistered CommenterDavidCH

It's all part of the show ... "see I tried to engage with them and this is what I get for my troubles! "

You deliberately post up provocative claptrap to by-pass the corruption of your science, expecting to go straight to "democracy" and be heralded for that ... explain yourself !

Sir, your slip is showing and it reads "prat".

May 28, 2012 at 1:14 AM | Unregistered CommenterStreetcred

To be fair to Myles it is a bit naff to have a caption contest running above a potentially interesting discussion thread that he may contribute to. There were a large amount of very good questions though that Myles didn't answer and you get the feeling he was never going to either.

We do know now that his belief is based on the last 50 years temperature (HADCRU anyway) record and I think many here can see lots of issues with that. My issues are many 1) the weather today is the same as far back as I can really remember (35 years) 2) I think you really not have to be looking to not see UHI/Land use change issues in the 20th century record 3) General worldwide glacier retreat over the last 200+ years is very strong evidence of warming over that period or at least reduced precipitation, so do the models represent that. I guess they have to subject a linear trend (reasonable assumption I would have thought) to match this in the model.

I can think of lots of other issues in the recent temp record too, so I hope Myles at least has an independent record of temperature to measure his models against. In a semi appeal to authority I do have more respect for an Oxford professor compared to an enviromental scientist from Lancaster getting a PHD from Newcastle and then getting to head up a UEA department...

I would also be very interested in discussing the methodology behind Myles project which from it's basic website docs seems one of the most extreme curve fitting exercises I've ever seen.

May 28, 2012 at 3:12 AM | Unregistered CommenterRob Burton

From the Ecclesiastical Uncle, an old retired bureaucrat in a field only remotely related to climate with minimal qualifications and only half a mind.

It seems possible that the Prof will not return to this blog, even to inspect, so these remarks are for others.

The Prof seems to deplore the standard of the communication of science to the public. However, it is my view that poor communication of modern science is both purposeless and inevitable. As a parallel, I suggest communication to UK citizens of a dispute over land in Papua New Guinea whose ownership is disputed by citizens of that country and which lies across a track leading to deposits of rare minerals used in mobile phones the UK. What difference does it make to the resolution of the dispute if the UK public are brought to understand Papua New Guinea customary land holding rights and the claims of the two parties? None in any sane world. Is it possible that the public, who have more immediate concerns, can ever be made to understand such matters? No. The parallel is clear. How can public understanding improve resolution of a scientific dispute? It cannot. And in the main not being scientifically educated, can the public ever be brought to understand? No – poor communication is inevitable.

However, if these arguments are dismissed, what do we have? The Prof has found the arguments put forward here misrepresent his meaning and he is both frustrated and bored. So he has withdrawn. In my very humble opinion which is very likely just plain wrong, the Prof’s intervention here is not exceptional when compared with others by other ‘warmists’ and his withdrawal not particularly remarkable. This is therefore a good instance of the difficulty of communicating between opposing sides of a scientific argument and in so far as this blog represents a public rather than a scientific forum, of communicating science to the public. These difficulties are not, of course, confined to the ‘warmist’ side: others in this blog have become bored and frustrated by ZDB and BBD and it may even be blog policy to prevent their contributions from being aired.

My observations only – not a polemic.

May 28, 2012 at 4:44 AM | Unregistered CommenterEcclesiastical Uncle

Although this is my first post on any climate forum, I've been following the debate for some time. My credentials to contribute anything technical to the scientific debate are zero, but I think I'm a fairly good example of a lay observer. I've got a somewhat dog-eared degree in Chemistry from thirty years' ago and have spent my career in software development. However, I've appraised myself of the major arguments for and against AGW and have followed many discussions and threads on realclimate and climateaudit and of course, I have read Andrew's book. Now, it seems to me (as a lay observer) that:

a) The behaviour of the climate science community (and especially the Mann, Jones et al group) has been shockingly poor in terms of them doing their science in an open, honest and unbiased way. How can I trust their interpretations if they hide the base data, bend the peer-review process to their ends, fail to properly archive and housekeep their data, fail to write well-documented and published analytical software and so on and so on?

b) The subsequent responses from the various scientific journals, institutions and boards of enquiry into the anomolies found by Steve McIntyre and others have, for anyone who reads past the headlines, been rushed, shoddy and apparently done only to present a 'nothing to see here' response for the media. They have all failed to engage the critics or to have properly answered their concerns. How can I seriously have any confidence that these investigations are anything other than a whitewash?

c) The world deserves something much, much better than this. If AGW is as real as many suggest, then we need to make serious, global policy decisions; and IPCC AR4 doesn't look like it's got the credibility to allow us to do this. I understand all the difficulties with proxies and such like, but why can't we build a rigourous review of the hockey stick data? Why do Myles Allen and others keep insisting that the 'science is proven' when it's clear that either it isn't, or else they have failed to convince the intelligent lay observer (i.e. people like me !) that it is.

d) While the world spends enormous resources on AGW research and associated responses (from wind-farms to CCS), we are collectively commiting an act of mass extinction on many of the earth's species from activities that are beyond any doubt or debate. I'm talking of destruction of habitat, deforestation, pollution, over-fishing and such like. That many of these are caused by over-population seems beyond reasonable doubt, but instead we focus on AGW.

Finally, IMHO, it seems that some posters here use insulting and derogoratory language when really it's unnecessary and unhelpful. I'm not surprised that Myles Allen has checked out. It's a shame really - I thought it was great to someone in his position engaging in this blog discussion. On a similar note, I think that Andrew has seriously dented his credibility/authority by launching a caption competition!

May 28, 2012 at 4:50 AM | Unregistered CommenterPaul Kaye

In response to Ecliastical Uncle (must start using a nom de plume!)...

The point about whether the general public understand scientific issues is not really the point (and I agree that asking them to do so is probably impossible). What *IS* the point though is:

a) that policy makers must have robust and informed advice, and

b) that such policy makers carry the public in whatever policy they wish to force upon them.

In both these aspects, it is essential that the proponents of the advice can face up to their detractors by convincing intelligent and informed people of their argument. The 'warmists', at least in the case of the hockey stick and climategate, have failed to do this.

May 28, 2012 at 5:06 AM | Unregistered CommenterPaul Kaye

Please correct the second sentence of the first long paragraph in my previous post to:

However, it is my view that communication of modern science is both purposeless and too difficult to do meaningfully.


May 28, 2012 at 5:09 AM | Unregistered CommenterEcclesiastical Uncle

May 28, 2012 at 5:06 AM | Paul Kaye

I know it might be asking way too much but you would have really hoped that "policy makers" having informed advice were the same people as being convinced "intelligent and informed people"

I could wish at least.....

May 28, 2012 at 5:13 AM | Unregistered CommenterRob Burton

Hi All,
I was in the papers last Tuesday through no initiative of my own
Then you were in on Friday with an article at Guardian Environment, the latest of many.

it was rapidly whipped up into a claim I was plotting to overthrow democracy, all without anyone taking the trouble to ask me what I meant.
But you said what you meant in the talk to communicators. You said “the way it’s going, the whole climate change issue will be played out by professionals, largely leaving the public out of the picture. That’s sad for democracy, but it may ultimately be the best for the planet.”
Then you said here that “pseudo-debates about the science” are “sad for democracy”. We understand that.
For my pains, I have now been called an "idiot", "prat", "arrogant" and I don't know what else.

So you’ve read all the comments
I do appreciate there have been a couple of thoughtful comments on this thread, but I'm afraid I'm going to have to sign off.
but have chosen only to mention the trivial ones.
Your behaviour here is the clearest expression of why democracy is threatened. You and others like you are free to express your views in a thousand friendly media venues. Those who disagree with you are not.
You’ve been praised by many here for bothering to address people who disagree with you. Then you go away without answering a single substantive point made by the many polite and intelligent people who are eager to engage with you.
It is your refusal to debate which is the threat to democracy. Come back and answer the points made here or be branded as just another irrelevant Al Gore figure from the Catastrophe Communication industry.

May 28, 2012 at 6:56 AM | Unregistered Commentergeoffchambers

May 28, 2012 at 3:12 AM | Rob Burton

There were a large amount of very good questions though that Myles didn't answer and you get the feeling he was never going to either.

Yes, this was my impression, as well. His opening shot - along with that with which he departed - suggests to me that he has failed to take note of the excellent advice offered by Lucia (and subsequently elevated to an update to the headpost by Steve) in the parallel thread at CA.

So, in addition to Poor Phil, and (if Suzanne Goldenberg gets her "revisionist" way), Poor Pete, we can add Poor Myles to the roster of beleaguered, misunderstood "climate scientists".

TonyN's link earlier in this thread to is a post that I found to be most enlightening. In fact, I learned almost as much from Tony's post as I did from the questions Myles chose not to answer here (and on CA).

At this point, not only has Myles demonstrated that his mode of "communicating" does not seem to include "say what you mean, and mean what you say" but also his whining about the caption thread strongly suggests that he's highly deficient in the humour department.

May 28, 2012 at 7:08 AM | Registered CommenterHilary Ostrov

Prof. Myles Allen received a shellacking over at CA as well.

May 28, 2012 at 7:45 AM | Unregistered CommenterStreetcred

Many thanks to Hilary Ostrov for the link to TonyN’s 2008 article. Myles has form as a climate catastrophe communicator.

Myles Allen
Perhaps the most disquieting thing about your intervention here is the reason yo gives for calling it off - the caption competition.
This is not the first photo to appear in the media showing a boffin and a pop star. It’s part of the staple diet of climate communication. If you have yourself photographed talking to pop stars, you’re going to get treated accordingly.
Having a laugh at your expense and calling you names is a kind of displacement activity. Nobody really thinks you’re an idiot. This is just a way of letting off steam in order to hide what we really feel when someone in authority starts musing in public, in front of an applauding audience of communicators, about the possibility of replacing democracy with something more to his taste.
What we feel is not “what a prat” or “how arrogant”. It’s more like a wave of fury, hatred and contempt - feelings which it would be most inappropriate to express on a blog about climate science.

So we let off steam by having a bit of a laugh, that’s all.

May 28, 2012 at 7:56 AM | Unregistered Commentergeoffchambers

I refer the reader to my comment in unthreaded. It was his turn in the barrel, he took some well-justified flak, and now he has indeed gone scuttling back saying 'you can't talk to those people'. Next!

May 28, 2012 at 7:58 AM | Unregistered CommenterRhoda

Rob Burton (May 28, 2012 at 3:12 AM)

I do have more respect for an Oxford professor compared to an environmental scientist from Lancaster getting a PHD from Newcastle and then getting to head up a UEA department...
Most of us probably share that feeling of respect, which is probably why Oxford professors like Allen (and his more junior associate Chris Huntingford) feel at ease musing about the end of democracy, while your Lancaster man is more likely to admit he was wrong and that his critics have a point. You can talk to Lancaster Man, (even though he rarely replies) while any attempt to argue with Oxford Man is likely to be interpreted as endangering democracy.

May 28, 2012 at 8:44 AM | Unregistered Commentergeoffchambers

Well I've read 'em all and my belief is that the true delivers in CAGW are still grasping at straws, it's a shame Myles Alleen I gave you your chance to change my mind and all I got was model this, model that.

But the worst part is you want to destroy democracy for 'The Cause'.

May 28, 2012 at 8:58 AM | Unregistered CommenterShevva

I too agree that Myles Allen came here, posted very little, addressed no substantive points and then complained and disappeared. If Richard Betts can come here and argued his case without getting the hump, why does Myles Allen have such a problem?

Simple advice to Myles Allen: if you want to come here and discuss everyone will listen and reply. It is robust, but its far more friendly than being a sceptical commenter at say RealClimate. For example, you are not censored and contributors here genuinely want a dialog. However, they are very intolerant of broad brush arguments and arm waving. Many substantive and important points were made to you and in parallel by others at ClimateAudit, including the very substantive points stated by many here (including me) and by the likes of Judith Curry and Craig Loehle at CA regarding the importance of establishing what the true natural variability is, in which case questions about the MWP and the variability of climate in the Holocene are critical for establishing the null hypothesis against which climate modelling should be judged. You have not addressed that question depsite it being presented several times. Pretending the MWP doesn't matter and that we need only to talk policy is basically a way of telling all these intelligent people that their opinions don't matter and we need to just shut up just listen to you. Sorry, but I for one don't accept that as substantive argument.

You should also remember, as was said above by Spence_UK, that many of us here are more than qualified working with models (in my case, lagre stochastic models of sub-surface geology, forward rock physics models, elastic wave propagation forward models, inverse problems and so forth) and can spot tautologies from a mile away. In my business, I work with far better conditioned models than in climate, I also to have to make predictions which cost ten to hundreds of millions of dollars to test. My predictions are actually tested, your model predictions can only be tested by waiting for decades. I have made enough predictions during my career that turned out to be wrong to have a little humility about my models in the face of the complexity of natural systems.

For me, thread winner goes to Spence_UK for a series of excellent posts. Wooden spoon goes to new guy Richard Montford...:-)

May 28, 2012 at 9:06 AM | Unregistered CommenterThinkingScientist

Myles withdraws. I guess we'll never know his view on AGW falsifiablity criteria.

The best I've been able to squeeze out of a Warmist is an agreement that, should the Antarctic icecap reach South Georgia, that person would consider the hypothesis refuted. Not much, I know, but it's a start.

May 28, 2012 at 9:15 AM | Unregistered CommenterBrent Hargreaves

Richard Betts said at May 26, 2012 at 10:49 AM in response to Phillip Bratby's question asking for evidence that the decade-to-decade global warming trend observed since the 1970s is largely caused by the increase in atmospheric greenhouse gas concentrations, "The evidence is explained here. Please read it!". Here was a link to chapter nine of the IPCC's AR4.

I took your advice, Richard, and am still ploughing my way through it. In the little time I've had, I've been concentrating on radiative forcings. I think most people here would not argue with the idea that CO2 is a greenhouse gas and that our emission of it will have caused an increase in global temperature. It's the forcings that count, right?

Anyway, In 2.9.1 of chapter nine it give estimates for uncertainties surrounding radiative forcings based on a quoted "level of scientific understanding" (LOSU). From this we get:

High LOSU - Low level greenhouse gases

Medium LOSU - Stratospheric and tropospheric ozone

Medium to low LOSU - Direct aerosol, Surface albedo (land A use)

Low LOSU - Stratospheric water vapour, Cloud albedo effect, Surface albedo (BC aerosol on snow), Persistent linear contrails, Solar irradiance, Volcanic aerosol,

Very low LOSU - Stratospheric water vapour from causes other than CH4 oxidation, Tropospheric water vapour from irrigation, Aviation induced cirrus, Other surface effects and last, but by no means least, Cosmic rays.

The above would seem to suggest that we know far less about forcings than it is often claimed by AGW scientists. Given all the uncertainties above, how is it possible to design a computer model that is capable of accurately predicting future temperatures based on forcings? As I said earlier, I'm still reading through the chapter and may have missed something. If so, it would be good if you could correct me.

May 28, 2012 at 11:03 AM | Unregistered CommenterSevad

Myles Allen

I am one who appreciated your comments here, although I do wish you would engage with the arguments and perspectives of some of the more thoughtful commentators here. The exchange on Climate Audit went a bit further (and I highly recommend that thread to all here). I think if you really begin to take account of some of the comments at Climate Audit by McIntrye, Curry, Loehle, Mosher, Lucia, Pielke, Jr. and others then you might have a more complete view on why these controversies are so difficult. Not to mention that there are many thoughtful comments on this thread, despite the occasional insults....

Realizing that you may not even see these words if you have indeed written us all off, I still want to say something for anyone to think about regarding communication and debate on these topics.

Some of the vehemence of responses here can be attributed to the larger issues of how climate policy has been debated (or not seriously debated) over the past 10, 15, 20 years. Not to mention the scorn and insults which have been directed at so many of us who are interested in issues as discussed on this and similar blogs.

However, I do think you should reflect upon how dismissive and disdainful, even contemptuous, your comments came across to many here. You have a particular take (or set of views) on which issues do and don't matter, and how they should be approached. But you did (whether you consciously intended offense or not is a distinct issue, I will assume you did not intend to be offensive) basically arrive telling everyone here that they are focused upon "irrelevancies" and that you would set us all straight.

I actually appreciate this, because I do have an enormous amount of respect for your learning and expertise in science.... but I also think that with regard to questions of public policy and decision making (particular areas of interest to me) you have barely begun to think about these matters.

Rather than write a whole essay here (I have gone on too long already), I will simply list some phrases you used at the top of this thread and in the video, and suggest that these words may mean very different things to you than to many of your listeners and readers. So, what all of us can reflect upon, perhaps, is that words like the following in this context of climate policy are (1) highly contentious and disputed, and (2) do not mean to many of "us" what you want them to mean.... or to put it another way, these phrases (merely listed here without context) can too easily give rise to misunderstandings and/or give offense, assuming your intentions here were something more than to say "bugger off you fools, and leave these matters to the grown-ups!"

But if the latter really is your view, on one level or another, then that also would account for some of the contentious moments here. Please think about the implications and various meanings of these words of yours, in the contexts of myriad events in the climate science controversies:

"pseudo-debates about the science"

"no room for public debate about the policy response"

"distracted by a debate over the Medieval Warm Period"

"keeping the public focused on irrelevancies"

"a problem we can solve without compromising fundamental democratic principles"

[from video of your talk]:

"... the way it's going, the whole climate change issue will be played out by professionals, largely leaving the public out of the picture. That’s sad for democracy, but it may ultimately be the best for the planet"

May 28, 2012 at 11:06 AM | Registered CommenterSkiphil

"Such a test is worthless. I could produce a model which invokes god to create life, then run that model without god, at which point life would not occur, and then declare god as the source of life. I've "proven" it with two model runs."


You can look at the key IPCC attribution graph. The so-called 'natural' global temperature curve shows absolutely no century-scale variablity whatsover. It is evident that only the assumptions about CO2 and related processes produce the warming that is seen in the 'natural+anthropogenic' curve. This, in turn, becomes 'proof' that the CO2 produce the warming? Heh.

May 28, 2012 at 12:04 PM | Registered Commentershub

Skiphill, how polite. How inoffensive. Like a stiletto in the ribs.

May 28, 2012 at 12:23 PM | Unregistered CommenterRhoda

Myles Allen (if you're still reading)

"the UEA e-mails called into question the integrity of the data"

I think you'll find that it was the integrity of the scientists that was called into question.

May 28, 2012 at 12:27 PM | Unregistered CommenterJames P

Myles Allen says in his "withdrawing" post that he has not criticised HSI. He hasn't because he hasn't read it! If he had he would have some understanding of the work that Steve McIntyre does and not categorize him as a paleoclimate scientist.

It was that post that caused me to categorize Professor Allen as yet another "wamist" who thinks he can convert sceptics with the usual appeals to authority, poorly thought through arguments and distortion of facts [Climategate] and then goes off in a huff when challenged.

May 28, 2012 at 12:46 PM | Unregistered CommenterJohn Hewitt

It is sometimes the result of years tending the groves of Academe that one becomes a pedagogue. One who must lecture rather than discuss, who expects to be listened to and obeyed, who treats everyone he meets as if they were one of his students. This has the unfortunate side effect of making the victim look to some like an arrogant prat and to go off in a huff when confronted. It is quite benign.

May 28, 2012 at 12:50 PM | Unregistered CommenterRhoda

May 28, 2012 at 11:03 AM | Sevad

Thanks for reading the IPCC chapter and for your excellent point.

It is not currently possible to "design a computer model that is capable of accurately predicting future temperatures based on forcings" - it is only possible to design one that gives estimates of future change based on current understanding, and these estimates have wide uncertainties as illustrated in this IPCC AR4 figure here.

(And incidentally, Myles Allen would probably be the first person to say this -
he is one of the firmest voices in warning people not to over-interpret climate models!)

However, despite the uncertainties, the overall current anthropogenic forcing is still almost certainly a net positive forcing (warming). This is why the future projections, despite having large uncertainties, all suggest an overall warming as a result of anthropogenic emissions. It is just the magnitude of warming that is uncertain.

At the risk of giving you more to read, if you are interested you can read more about this here.



May 28, 2012 at 1:50 PM | Registered CommenterRichard Betts

May 28, 2012 at 1:50 PM | Richard Betts

"At the risk of giving you more to read, if you are interested you can read more about this here."

I don't doubt your good intentions in linking to this, but isn't part of the problem (people talking past each other) that to most people here, pointing readers to the IPCC reports is rather like directing them to the Guardian for impartial coverage of the Peter Gleick affair.

Unfair? I don't think so, for as long as the IPCC has not turned its back on the people who, on ethical grounds, would not be tolerated in any other industry or field. And since in many cases the IPCC is those very same people, we know that is not likely to happen.

May 28, 2012 at 3:11 PM | Unregistered CommenterHK

Thanks for taking the time to post here, greatly appreciated. :-D. As a duly-appointed representative of the public, I thought I better chime in here, expose my ignorance for you to see.

Of course that you realize that the hockeystick and suppression of the MWP (including in Wikipedia) is the main line of evidence in citing the 'unprecedented' nature of the recent rise in temperature? It wasnt so irrelevant at all for AR4.... And the fact that the trees aren't tracking this recent rise in temperature completely undermines the entire tree paleoclimotology enterprise....?

Which is why they HAD to 'hide the decline' - its the dirty family secret about the whole field of research - if word got out, then Mike Mann would be out of a job. And so....Briffa cherry-picked the Yamal dataset to find the one abberant tree to provide a compliant chronology that was over and over in these reconstructions.

Of course - you know and I know that we have been lied to about these things. Now you're trying to cover this as Irrelevant - because you know this and want to not discuss this. So now it's about the temperature record. Which of COURSE has not been fiddled with either, correct? James Hansen would never do that would he?

May 28, 2012 at 3:18 PM | Unregistered CommenterLearDog

Richard Betts’ reply (May 28, 2012 at 1:50 PM) to Sevad thanks him for his “excellent point” which was that current levels of scientific understanding, as detailed in chapter 9 or AR4 “suggest that we know far less about forcings than it is often claimed by AGW scientists”.
Betts goes on to say that current computer models are not capable of accurately predicting future temperatures based on forcings, but only “based on current understanding”, which, as AR4 chapter 9 explicitly says, is low for many factors, and he finishes

However, despite the uncertainties, the overall current anthropogenic forcing is still almost certainly a net positive forcing (warming). This is why the future projections, despite having large uncertainties, all suggest an overall warming as a result of anthropogenic emissions. It is just the magnitude of warming that is uncertain.
(He also says “Myles Allen would probably be the first person to say this” but that we shall probably never know).
I’m sorry Professor Betts, I don’t want to be a choplogic, but it seems that there is absolutely no disagreement between yourself and the vast majority of commenters here, who all accept that anthropogenic emissions are likely to cause an unknown magnitude of warming. So why won’t the professionals who come here like yourself and Myles Allen 1) accept that we agree with you on this essential point and 2) answer head on the questions put here, about the circularity of the model argument in AR4 chapter 9, the importance or otherwise of the Hockeystick, and many many others?

May 28, 2012 at 3:20 PM | Unregistered Commentergeoffchambers

Dr Betts, you say "[i]t is just the magnitude of warming that is uncertain" but I believe you should have added "...and its relevance with respect to natural variability" since this may well be the most important factor in determining our social/political response to AGW.

May 28, 2012 at 3:53 PM | Unregistered CommenterDave Salt

One additional comment about Dr Betts' last post (May 28, 2012 at 1:50 PM). To simply state that "[i]t is just the magnitude of warming that is uncertain" is rather weak in this context, as most skeptics would agree that some warming is likely (i.e. AGW probably is real) but are mostly concerned with statements about the likelihood of catastrophic levels of warming (i.e. belief in CAGW is currently unjustified). In fact, taken solely on your recent statements, we could also conclude that you are in complete agreement with Professor Richard Lindzen!

I think it would have been far more constructive to address some of basic concerns that have been raised on this thread (e.g. my posts on May 26, 2012 at 1:49 PM & May 27, 2012 at 4:48 PM), but I do appreciate your efforts to engage this forum.

May 28, 2012 at 4:31 PM | Unregistered CommenterDave Salt

"[i]t is just the magnitude of warming that is uncertain"

Well, yeah. And the sign, of course. Apart from that we are all in total agreement.

Seriously, it would be nice if some smart person from the area of control theory could give us a guess of the limits of sensitivity. Does the climate run away against the stops? Cold side or hot? If it does not, there must either be a limit to how much positive feedback there is or the whole idea of a consistent sensitivity figure of so many watts/sq m or degrees per doubling is not a realistic description of the mechanism (which would be my guess).

May 28, 2012 at 4:44 PM | Unregistered CommenterRhoda

"I was in the papers last Tuesday through no initiative of my own, but because I was asked by Intel to talk to their technology ambassador who happens to be"

Ah, that's completely innocent then. It wasn't like you were in any position to refuse to take part in the silly charade.

Gangsta music meets gangsta science. That was never going to end well.

May 28, 2012 at 5:24 PM | Unregistered CommentersHx

Hi Myles:

Did ask you watcha gonna do with all that junk, all that junk inside your trunk?

May 28, 2012 at 6:49 PM | Unregistered CommenterJungle Jim


Thanks for your reply at 11.03am on May 28. Thanks also for the additional reading! Whilst, like some other posters, I doubt the trustworthiness of the IPCC, I'll endeavour to read everything because I know how frustrating it is when warmists dismiss sceptics' references.

As for your your latest comment to me, can you back up the point that "despite the uncertainties, the overall current anthropogenic forcing is still almost certainly a net positive forcing (warming)" and "This is why the future projections, despite having large uncertainties, all suggest an overall warming as a result of anthropogenic emissions."

I'm having difficulty reconciling the raft of uncertainties surrounding forcing with the claim that net forcing will almost certainly be positive. I can cope with the idea that the uncertainties make it impossible to give an accurate picture about future forcing but why is it assumed that the overall forcing cannot be negative?
When so little is known about some of the issues, are there no computer scenarios which project net negative forcing and if not, why not? Donald Rumsden's famous quote about "unknown unknowns" springs to mind.

May 28, 2012 at 7:48 PM | Unregistered CommenterSevad

Sorry, Richard, I am of course referring to your reply at May 28, 2012 at 1:50 PM.

May 28, 2012 at 7:50 PM | Unregistered CommenterSevad

Rumsden = Rumsfeld

May 28, 2012 at 10:23 PM | Unregistered CommenterSevad

RB:' It is just the magnitude of warming that is uncertain'. As a pure mathematician let me turn this into a conjecture for you, assign a positive epsilon... Over to you.

May 28, 2012 at 10:24 PM | Unregistered CommenterDavidCH

I think you will find that the mainstream climate community is privately much 'concerned' that we are about to enter a grand solar minimum for much of this century, rather than, as one might suppose, be delighted. We, or our descendants, shall see...

May 28, 2012 at 11:38 PM | Unregistered CommenterPharos

Dr. Allen,
The instrumental record, and particularly the satellite records indicate warming since 1998 has not been significant. Warming occurred at the same rate and similar magnitude from 1910-1940, a time period when CO2 didn't change much. Anyone who has not pre-determined an interpretation of these observations would take them to be very nearly definitive evidence that CO2 is not the major driver of the climate system. Those who have already decided on a narrative manage to find a way to fit these observations into the narrative or to "adjust" the observations until they correspond with the narrative. I am not implying some grand conspiracy here or even an intentional act of deception. However, during my 30 years as a biomedical scientist, I have learned that it is remarkably easy to see data or methods of analysis that fit our desired narrative as valid and to find "problems" with the other data. This natural tendency is amplified to the point of being virtually irresistable when research funding and career advancement are dependent on the current narrative. When climategate first brought my attention to climate science, I was shocked at the type of work that was being published (e.g., a PNAS paper predicting mass migrations from Mexico to U.S. based on GCM regional model output fed into a model for crop yields which were then fed into a model for migration). Papers with NO data but only output from unvalidated models are not featured (and are rarely acceptable) in any other scientific field. Why are they featured in climate science?

May 29, 2012 at 1:34 AM | Unregistered CommenterStephen Pruett

Although most sceptics will agree with Richard that it is simply the magnitude of warming that is uncertain, this doesn't mean that there is no remaining disagreement. Richard imagines that the level of warming, although uncertain, will be enough to cause harm, whereas the sceptics feel that the effect is unlikely to be significant.

The reason for the difference in perspective lies in the weight given to natural effects, whether those effects be additional external forcings not included in climate scientist's calculations, or natural variability resulting from the non-linear nature of the climate system. It certainly seems to be true that climate scientists (whether mainstream or sceptical) have no widely accepted explanation for natural variability (**), even though analysis of reconstructions strongly suggests that it is an important and possibly dominant factor.

To my mind, this explains only too clearly why Myles would prefer to downplay the relevance of reconstructions. I am more puzzled by Richard's position though. He seems to accept the importance of reconstructions (on another thread he said that "changes over the last century appear to be unusual in the context of the last millennium"), and yet his sticking point apparently lies in accepting that the reconstructions do indeed provide clear-cut evidence of powerful natural variability over time-scales greater than a few decades (a variability that unsurprisingly is not simulated by models).

I think that Richard would find it easier to to maintain a credible position, if he explained why he does not accept the evidence for natural variability (*).

(*) For example,

Low frequency weather and the emergence of the Climate

Stochastic and scaling climate sensitivities: solar, volcanic and orbital forcings

Do GCM's predict the climate...Or low frequency weather?

(**) There is a reasonably deep literature on issues related to this topic beyond the McGill group. It is worth mentioning that the same kind of variability found in climate records is also found in many other physical systems, and indeed there is an enormous literature going back to the 1930s that tries to explain how it arises (the ITIA group mentioned above by Spence_UK has contributed to this effort in the context of hydrology and climate). Nonetheless, providing a general explanation for it, is regarded as one of the major unsolved problems in physics (and so it is probably a little unreasonable to expect Richard and co to have a ready explanation). The essential point though is that it most certainly does exist in the climate records and therefore does need to be properly acknowledged and taken account of in any credible theory, whether mainstream or sceptical.

May 29, 2012 at 10:00 AM | Registered CommenterPhilip Richens

May 28, 2012 at 7:48 PM | Sevad

There is high confidence in the net anthropogenic forcing being positive (warming) because:

1. The central estimate of the GHG and tropospheric ozone forcing is large, and the uncertainties are small

2. Although the uncertainties in aerosol cooling are large, the central estimate is smaller than that for the positive forcings and only the extreme end of the range gives a cooling that is similar to the GHG warming.

There is no strong evidence that the cooling offsets the warming. If you assume the greatest possible cooling from all negative forcing and the smallest possible warming from all positive forcings then you just about get an overall cooling. However that is at the very, very unlikely end of the range of possibilities. See IPCC AR4 WG1 Figure 2.20 and associated text.

It is important to note how "Level Of Scientific Understanding" (LOSU) is defined. It is based on the amount of evidence and the extent to which this evidence is consistent. If there are few studies, or there are many studies which disagree, then LOSU is low. There is only a high LOSU if there are many studies and they agree well. The AR4 text and tables describing reasons for the LOSU for each forcing source is here.



May 29, 2012 at 1:16 PM | Registered CommenterRichard Betts

May 29, 2012 at 10:00 AM | philiprichens

Hi Philip

I think you've misunderstood my position.

Richard imagines that the level of warming, although uncertain, will be enough to cause harm

No - I don't "imagine" anything, and neither do I claim that anything "will" be the case.

I am convinced by the balance of evidence, theory and modelling that unchecked warming is sufficiently likely to cause harm that it makes sense to take steps to avoid this, through some combination of emissions reductions and adaptive planning.

I am highly uncertain about how much warming is "harmful" (which is why I spend my time doing the science to help establish that!), but heading in the general direction of "harm" is not sensible if there is a choice in the matter.

Of course I accept that natural variability exists! And yes indeed it may have made some contribution to recent warming, but I've not seen anything which convincingly shows it is the dominant contribution.

You cite 3 papers from the same authors, but none of these claim that recent warming is predominantly due to natural variability. Indeed they specifically missed out the 20th Century, saying"

In order to determine the natural variability (i.e. without strong anthropogenic effects), we focused on the pre-1900 period

So, it's not that I "do not accept the evidence for natural variability", it's more that the papers you cite are not actually evidence for what you say! :-)



May 29, 2012 at 1:59 PM | Registered CommenterRichard Betts

Dr. Allen's response keeps setting off my gobbledygook detector. Is it just me? So many words and yet he never explained why he thought "Climategate" was about the temperature data from CRU?

May 29, 2012 at 2:57 PM | Unregistered CommenterC. Bruce Richardson Jr.

Hi Richard(Betts),
What is the range of century-scale interval variability that models display?

May 29, 2012 at 3:12 PM | Unregistered CommenterShub

Hi Richard,

Thanks very much for your reply, it is much appreciated. Here are my responses.

I am convinced by the balance of evidence, theory and modelling that unchecked warming is sufficiently likely to cause harm …

I assume you mean “unchecked warming caused by CO2 emissions”. If so, then I’d like to briefly review what I think you mean when you talk about “the balance of evidence”. Please tell where I have misunderstood your position.

Your evidence includes the GHE -- which I obviously accept as basic physics. The important issue is how that plays out within the actual climate system, because by itself, the effect would be small. Therefore you also point to additional evidence about how it plays.

From your earlier comments, I understand this evidence includes chapter 9. I’m sure you remember that we’ve discussed the issues with the chapter 9 attribution argument in some detail. Do you have anything to add to that discussion?

Other than that, I remember your citing a 1970s paper that predicted a 0.6 degree rise in temperature, and the paleo record, possibly limited to the last 1000 years.

Is there anything else, or is that it?

You cite 3 papers from the same authors, but none of these claim that recent warming is predominantly due to natural variability.

The first paper I referenced contains a decent review of the literature on this issue. The research in question has been ongoing since before the AGW scare began. I've not found your precise quote, but I guess you may be referring to section 4.4? Here, they do indeed focus on the pre-1900 period, but simply in order to demonstrate that the variability they point to is not an artifice of the inclusion of 20th C temperatures. They say,

In order to demonstrate that the basic type of statistical variability is not an artifact of the inclusion of exceptional 20th C temperatures in fig. 9, we also show the corresponding Haar structure functions for the earlier period 1500-1900.

The last two papers expand on themes introduced in the first.

Of course I accept that natural variability exists! And yes indeed it may have made some contribution to recent warming, but I've not seen anything which convincingly shows it is the dominant contribution. … So, it's not that I do not accept the evidence for natural variability, it's more that the papers you cite are not actually evidence for what you say!

I'm very pleased that you do accept the existence of natural variability, and I hope by this you mean natural variability on decadal and larger time-scales. I'm a little surprised you think the papers I mentioned don't support what I said about variability. Since I’ve spread this out over several comments, let me recap:-

A/ The fluctuations in most temperature records increase on time scales starting at about 30 years and going out to 100,000 years. This is the climate regime.

B/ The climate regime scaling behaviour is observed in modern Holocene reconstructions, in ice core reconstructions and in the instrumental record.

C/ The climate regime scaling behaviour is not seen in Holocene reconstructions circa MBH. Reconstructions from that time are outliers from the point of view of their scaling behaviour.

D/ The climate regime scaling behaviour is not generally seen in GCMs. Hence GCMs are currently unable to simulate climate changes, even though they are very good at simulating weather. It is not known whether this is because of unaccounted external forcings or unaccounted internal natural variability. Either way, it is unaccounted.

You will find all of these findings explained in the papers I mentioned, together with caveats etc.

AR4 chapter 9 uses a comparison between GCM simulations and the instrumental record to assert that 20th C temperature changes are attributable mainly to human CO2 emissions. The facts I mention that argue against this conclusion are:-

1/ Reconstructed natural variability on time-scales > 30 years has similar statistical properties to 20th century changes.

2/ GCMs are unable to simulate this variability.

Furthermore, as we discussed previously, modern reconstructions of solar forcing are significantly changed compared to those used in AR4, and this also reduces the credibility of the chapter 9 argument. As you will no doubt point out, the modern forcings are smaller. My response to this will be that this simply reflects the inability of GCMs to simulate 30+ year variability using the currently accepted forcings.

May 29, 2012 at 3:51 PM | Unregistered Commenterphiliprichens

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