The scientific community is polarised on the matter of climate change. On one hand there are those within what might be called the climate research establishment. They should know what they are talking about, and generally support in public the thesis of dangerous global warming.
On the other hand there are those – mainly from other disciplines or from the various ranks of amateur scientists, but nevertheless also including a fair number of quite respectable climate scientists – who for one reason or another are sceptical about climate change. They openly maintain that the whole concept of dangerous man-made global warming is probably nonsense.
The scientists in the middle tend to say very little. At least in public.
The problem for the scientific community is that this polarisation is seriously threatening the public’s perception of the professionalism of scientists in general.
Setting aside the issue of who is right in the debate, it seems that some of the more vocal of climate researchers have fallen into a mode of open and almost vicious denigration of climate sceptics (“deniers” is the rather offensive popular terminology of the day).
They insist that only researchers directly within the climate-change community are capable of giving authoritative advice; and they insist that one can find true and reputable science only in peer-reviewed climate literature.
There are also reports of highly unscientific practices – for instance, that outsiders and known sceptics are denied access to important data on which climate science is based.
Sceptics on the other hand have in many cases been too personal in their attacks on climate science and climate scientists. They have made full use of the various sceptical climate weblogs to get around the discipline of peer review.
A lot of their scientific arguments are “hairy” to say the least; and in general they have not been greatly constrained by the checks and balances built into the normal scientific system.
Some of them just like being a nuisance.
All this is discussed extensively and publicly on the web. There are arguments to explain and justify the less flavoursome attitudes of either side.
But whatever one might think of the rights and wrongs of the business, the fact remains that a situation has developed which is reminiscent in many ways of religion in the Middle Ages.
The priests of that time opposed translation of the scriptures from Latin into the local languages. Only people fully trained in the theology of the time were capable of interpreting the scriptures correctly, they said. It would, they said, be highly dangerous to allow non-trained people to have direct access to the Word of God because the chances were high that they would get it wrong.
And the priests of the time were not exactly backward in applying their peculiarly nasty forms of denigration on those who thought otherwise about the matter.
Suffice it to say that, despite their strong whip hand (there was no internet at the time!) they ultimately lost both the battle and much of their public support.
All of which leads to the following.
Since the research establishment is presumably the more “grown-up and sophisticated” of the two sides in the debate – it certainly has by far the lion’s share of resources and public access – it seems appropriate to expect the establishment to take the first steps in any attempt to bridge the divide between the sides.
One of the steps might be to formally recognise that not all climate sceptics are rogues and vagabonds.
We should remember that it is probably more of a rule than an exception for new ideas in any particular field of research to come from the outside. We should also remember that some weblog sceptics have access to a quite remarkable store of unpaid and enthusiastic scientific labour.
Perhaps however, the very first step should be for climate scientists to make a conscious effort to read some of the documentation appearing in the more respectable sceptic weblogs: Climate Audit and Whats Up With That for instance.
Climate researchers need to develop a first-hand appreciation of the mind-set of the sceptics, and thereby understand how best to engage with them, to take advantage of their ideas (and perhaps of their access to unpaid enthusiasts!), and to be positive and helpful when identifying errors in some of the more extreme ideas.
The Conversation
Comments (54)
Comments on this article are now closed.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
I had hoped that The Conversation would be a refuge from articles such as this.
Garth would have a point if there were legitimate scientific arguments on both sides of the debate. The trouble is, there aren't. The evidence is so strong for the reality and importance of anthropogenic global warming, that those scientists who disagree can only reasonably be described as either uninformed or as deniers.
Far from the research establishment having the lion's share of public access, it is the deniers…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
The idea that there are no legimitate ideas among sceptics is risible. At the Cambridge conference on climate change last week, we heard Mike Lockwood, a man in the AGW mainstream, describe the ideas of Henrik Svensmark, a sceptic, as "beautiful". The two men disagree on the impact of Svensmark's ideas, but to suggest that they are illegitimate is not, I think, a tenable position.
Prof Ashley speaks of Patridge as conspiracy theorising. Again, an anecdote from the Cambridge conference sheds some…
show full comment
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Svensmark's cosmic ray hypothesis was indeed interesting when he first proposed it (13 years ago I think), but it is has failed as an argument against AGW.
Svensmark, far from being ignored, has been able to publish a number of peer-reviewed articles on the subject. This is how science works: come up with an idea, publish it, and see how the reaction pans out. In the case of Svensmark's theory, the reaction from experts who have looked very closely at this specific issue is clear: interesting idea…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
By strange coincidence, some new results in support of Svensmark's theories.
http://calderup.wordpress.com/2011/05/15/accelerator-results-on-cloud-nucleation/
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
OK, I think you are admitting that there are legitimate ideas among sceptics, but you disagree with them. That's fine, but I think it would be better if you said so clearly.
You seek to denigrate Svensmark by for accepting an invitation to speak at the Cambridge conference. This is fallacious reasoning and seems to me to be a rather low tactic for a full professor to adopt. I shudder for your students if this is the quality of logic you teach. Is Phil Jones similarly "reduced to talking at embarrassing conferences"? Mike Lockwood? John Mitchell? I counted four fellows of the Royal Society in attendance, although there may have been more.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
No, I stand by what I said, that there aren't any legitimate scientific arguments on the other side of the debate, where the debate is on the reality and importance of anthropogenic global warming. You gave the example of Svensmark, and I pointed out that he had an interesting idea 13 years ago, but subsequent study has failed to show that it has a significant effect on global warming. And I'm well aware of the CLOUD collaboration that you mention below.
I also stand by my comments on the Cambridge…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
You were originally arguing that there were no legitimate arguments put forward by sceptics. Despite one of Svensmark's direct opponents describing his ideas as "beautiful" you maintain that his contributions are "illegimitate" because he has not put forward a fully documented alternative hypothesis. So we elide from "he has not made a legitimate argument" to "he has not put forward an valid alternative hypothesis". You shift the goalposts and the burden of proof at the same time (Epic fallacy…
show full comment
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Sorry, but you are putting words into my mouth, again. Where did I claim that Svensmark had to put forward a fully documented alternative hypothesis? My argument has remained consistent, your distortions of my argument are changing with every post.
I'm not interested in verbal sparring, which seems to be your modus operandi. I'm interested in some evidence that a sceptic has put together a viable hypothesis that shows that "dangerous man-made global warming is probably nonsense". So to disprove…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
The problem as posed is not phrased in scientific terms. The phrase "dangerous manmade global warming" is not a hypothesis in itself. Something like "The world will warm at 2deg/century if emissions follow the A1B emissions scenario" might be more like it. If this indeed encapsulates the AGW hypothesis as formulated by the IPCC, then we can discuss showing it is nonsense. However, one scientist I discussed this with at Cambridge told me that 2deg/century is not testable, leaving me with the impression that AGW is somewhat pseudoscientific.
So, could you clarify what it is you are asking me to falsify and then we can discuss further.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Well I can't say that I'm surprised that you have retreated into semantics to try to cover your inability to identify any convincing theories from the sceptics.
Let me save you some trouble: there aren't any! From Svensmark's galactic cosmic rays to Plimer's bizarre claim that underwater volcanoes emit more CO2 than humans, the sceptic arguments are all fatally flawed.
As for the phrase "dangerous manmade global warming", I agree that it is imprecise, but it is from Paltridge, not me. I only presume…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
I disagree, on two counts.
Firstly, there is no requirement for sceptics to offer an alternative hypothesis, merely to show that the AGW hypothesis does not accord with reality.
Secondly we do not test the AGW hypothesis on its ability to hindcast but on its predictive ability, an area where the IPCC's models show little skill. None predicted the slowdown in warming since they were issued in 2000. There is clearly something missing from the models. The AGW hypothesis is incomplete.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Hilarious! You are giving everyone reading these comments a textbook example of how denialists operate. Having failed to give an example of any viable theory put forward by the sceptics, you now switch tack.
With reference to the climate models, of course they are incomplete. They will never be able to predict every bump and wiggle of the future climate. However, what they do do is conclusively show that the surface temperature record can not be explained without including anthropogenic CO2, and the observations are well within the uncertainty envelope of the models.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
I'll post a new comment so we don't indent so much.
Misha Ketchell
(Editor, The Conversation)
That's a strong response Michael. I think on balance you're right -- certainly an embrace of unfounded conspiracy theories in the name of balance is a total croc and a cop out (see, at times, The Australian newspaper) But there is a perception problem that can be created when scientists are too dismissive of their critics. I think the warning to be careful on that front isn't too far off the mark.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Certainly perception is important in our attempt to persuade the public. But the sort of pathological nonsense that comes out of climateaudit and Watts Up With That is simply beyond worth considering.
As Garth says, there are indeed some scientists who are sceptical of climate change, and some of these are very vocal, but why do they have to resort to weblogs and OpEds in order to publicise their ideas? Why can't they provide good evidence in a peer-reviewed paper? Why don't they turn up to the…
show full comment
woolfe
(logged in via Twitter)
Instead of sneering and juvenile name calling why not answer the fundamental questions. How much is a low CO2 economy going to cost? What is it going to do (reduction in world temperature).
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
I had hoped that comments at The Conversation were moderated and off-topic ones would be deleted. The questions that woolfe raises are entirely unrelated to Paltridge's argument.
For what it is worth my answer is: a low CO2 economy is going to cost an enormous amount of money to set up, and unless the major CO2-emitting countries in the world follow along, it will have a negligible effect on world temperatures. The flip-side to this is that the longer we wait, the more expensive it will become, and if we wait indefinitely, it will end in catastrophe for civilization.
So, take your choice: (1) expensive action now, (2) much more expensive action in the future, or (3) the end of civilization.
Jane Rawson
(Editor, The Conversation)
Hi woolfe, I think you're in the wrong place. This article is about how we discuss climate change. However, there are many articles on The Conversation about a low-CO2 economy. This one was published last week: http://theconversation.edu.au/articles/its-the-economy-stupid-why-australia-should-support-a-carbon-tax-1719
Steve Sherwood
(Co-Director, Climate Change Research Centre at University of New South Wales)
I would love to have the time to troll through the blogosphere and digest all the arguments out there against mainstream climate science. Unfortunately unlike Garth I am not retired and have a full time job doing research and teaching. The place for this "debate" to happen is in the scientific literature, where contrarian papers do occasionally appear. These papers are far from ignored, they receive very high citation counts. I have yet to see a single one of them, however, that is not fatally…
show full comment
Bob Beale
Journalist (logged in via email @beale.org)
This shallow and disappointing analysis gives no insight into the real polarity that exists around climate science - not with the science itself (because there is genuine and overwhelming consensus compelled by evidence and not belief or personal opinion), but with the polarised political and ideological responses to its core message.
I accept that there are different brands of scepticism about the science, a little of which can be taken seriously. But when the Bob Carters of this world, for example, doggedly insist in the face of all contrary evidence that the world is cooling, it is a self-evident matter of fact - not invective - that they are deniers. When the Christopher Moncktons of this world claim that the scientific consensus on climate change is fabricated as part of a massive global conspiracy to install a communist world government, what else to accurately call them but conspiracists? If they don't like being labelled correctly, that's their problem.
Bob Bobsson
Mr (logged in via email @hotmail.com)
By and large the scientific community isn't actually that polarised. Yes, there are certainly some scientists that contest the science, but they're certainly not nearly as profuse as you suggest. They are still a fringe and still severely in the minority on the issue.
Joey Rumbold
(logged in via Facebook)
when someone writes that in the deniers/sceptic community there are "fair number of quite respectable climate scientists" my question is who ? give us some examples or a reference.
And the other question is if all this denier/sceptic "research" is so good why does it not appear my peer viewed sources ?
And I always fine it painful when a writer says that language is used by one side in "vicious denigration" then throughout the article uses loaded language to support one side and denigrate the…
show full comment
Wright B Hindyou
(logged in via Twitter)
It's always instructive to see the Warmist brigade trying to project the 'conspiracy' label onto the Skeptic camp when in fact all the talk of conspiracies comes from the Warmists themselves.
The man-made global warming movement isn't a conspiracy any more than the Mafia is a conspiracy; it is a group of people with strong vested interests which lie in a common direction, whether they be scientists, politicians who use the scientists' work for their own ends, journalists who feed off the sensation-mongering or grass-roots eco-socialists.
They all win if they can keep the scare going, but given their track record, any conspiracy they tried to cook up would be bungled so badly as to be obvious within minutes.
Megan Clement
(Editor, The Conversation)
You can check out Professor Stephan Lewandowsky's response to this article here: http://theconversation.edu.au/articles/climate-change-logic-lost-in-translation-1817
Dean Moriarty
(logged in via Twitter)
Wow. Never thought I'd read anything as reasonable re: climate scepticism here.
As I commented on Ross Garnault's article a few weeks ago ("When the science is so clear, why is the argument so clouded?"), the mind of the climate sceptic really does need to be understood.
Maurizio Morabito
(logged in via LinkedIn)
I do welcome Michael Ashley's comments. As long as there's people like him shouting around the blogs, it'll be fairly easy to demonstrate to the general public the dangerous, fundamentalist, anti-science mindset that is common among AGW catastrophists.
ps why is only Andrew Montford debating with Ashley? I think there is an even more fundamental disagreement here, ie Ashley vs Paltridge. One talks of "pathological nonsense", the other of being "positive and helpful". Unless the blog post's author wants to be positive and helpful about pathological nonsense?
Guido Tresoldi
(logged in via Facebook)
The problem is that this scientific issue has been politicised, where taking a particular view is generally associated with either a 'progressive' stance (climate change advocates) or a conservative one (climate change skeptics). And that's not surprising as limiting climate change would involve some modification and 'interference' of the market economy which is an anathema to those on the centre right of politics.
rupert fairfax
(logged in via Twitter)
Steve Sherwood: As the co-director of UNSW's Climate Change Research Centre you must be so very proud of your very own Jason Evans and Katrin Meisser for doing that fabulous rap song on Hungry Beast the other night. Nothing says "serious" like a bunch of brainiacs shouting the f-word (and the mother-f word) over and over again on prime time TV. And that line about "sucking d*** in Copenhagen", I guess that was peer-reviewed too.
Seriously, there can be no doubt about AGW and the need to combat it. Why then do you allow two of your most senior scientists to demean and debase the cause with those sort of adolescent antics. The PhD students who took part are probably too young to know better. But for Evans and Meisser to be involved is just an absolute disgrace.
Your unit has just handed the Bolts and Carters a powerful weapon. Disciplinary hearing called for, no doubt about it.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
Michael Ashley
What a strange response from a university professor who doesn't like verbal jousting. What I have suggested in terms of how to demonstrate that AGW is wrong or at least overstated, is bog-standard Popper. I'm not sure why any scientist would find this "hilarious". There is no need to come up with an alternative hypothesis, simply to falsify the one put forward. You say I have changed my story, but I have been trying to get you to explain some way in which the hypothesis you advance can be tested since we started this exchange.
You haven't disputed my proposal of 2deg/century as a test of the AGW hypothesis so I'm assuming that you accept its validity. Please tell me if I'm wrong in this assumption. If it is indeed a valid test then it should be quite simple to test whether the difference between the IPCC's 2deg/century and the actual temperatures can be accounted for by the short-term variability, right?
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Once again you are distorting my arguments. You say that what I find hilarious is how you propose to demonstrate that AGW is wrong. This isn't what I find hilarious. What I find hilarious is the way in which you duck and weave and distort my arguments, all the while presenting no evidence whatsoever that the sceptics have made any useful contribution.
And yes you are also wrong in your assumption that I accept the validity that 2deg/century is a test of AGW.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
More verbal jousting. You regard it as "quite an admission" that I don't accept the validity of your 2deg/century test? That wasn't an "admission", just common sense.
The sceptics shouldn't need me, or anyone else, to tell them how to falsify AGW. Do you think that scientists sit around and wait to be told how to falsify theories?
You have already admitted (see I can play this game too) that the sceptics don't have any valid alternative hypotheses. So this leaves them with having to show that AGW is not a significant influence on the climate. No one can put a simple figure on this (e.g., 2deg/century). It requires a careful study that establishes the expected influence of AGW, and then shows how the climate is changing in a way that is substantially different from that, where "substantially" requires consideration of uncertainties. Your demand for a simple test such as 2deg/century is never going to be satisfied.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
There is no point in trying to push me on whether any particular scenario would be a problem for AGW. The best approach is to get a bunch of experts together to review all the published scientific evidence and summarise the state of our knowledge. What I am describing is the IPCC.
If AGW has problems, then it will become evident in the peer-reviewed literature and will be picked up in future IPCC reports.
If there are sceptics out there who think that AGW is nonsense, then they should have a moral…
show full comment
Maurizio Morabito
(logged in via LinkedIn)
A bunch of experts got together in 1935 and decided to reject Chandrasekhar's work on the upper bound for a white dwarf's mass. That meant wasting at least 30 years of astrophysics. Hopefully Prof Ashley knows a thing or two about that.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
Wow. That's quite an admission. The need for a public policy response is predicated on scientists' predictions that temperature will rise. Yet when the temperature fails to rise, this is not a valid test of the hypothesis. But you are not willing to say what is a valid test.
Amazing. Right up there with homeopathy.
Maurizio Morabito
(logged in via LinkedIn)
Actually, homeopaths do mention anecdotal evidence to support their ideas.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
Well 2deg/century is what the IPCC communicated as the likely outcome. One assumes that you accept that the IPCC report is "a careful study that establishes the expected influence of AGW"? We should note in passing that it is primarily on these predictions that public policy responses are predicated.
Can you clarify what you mean by the rest of the paragraph though. I agree that you need a careful study showing that recent changes in temperature are substantially different to the IPCC's 2deg/century, and I agree you need to consider the uncertainties to do so. But do you agree that if such a study did demonstrate a substantial difference then this would be a problem for the AGW hypothesis as currently framed. I fancy you don't, based on your last sentence, but I'm not sure, which is why I'm seeking clarification.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
I am now completely confused. We are discussing falsification of the AGW hypothesis. You say I need a "careful study that establishes the expected influence of AGW" and I give you the IPCC report. You say I need then to show that "the climate is changing in a way that is substantially different" to expectation. I agree with you.
Then you say that even if the climate is changing in a way that is significantly different from expectation you will not accept it as problematic for the AGW hypothesis??!! Are you serious?
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
You say that I said "even if the climate is changing in a way that is significantly different from expectation [I] will not accept it as problematic for the AGW hypothesis."
Where on earth did I say that?
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
No, I didn't say that either. What I said was that "there is no point in trying to push me on whether any particular scenario would be a problem for AGW."
You seem to want me to say something like "if the 2deg/century trend is actually measured as 1.8deg/century for 10 years beginning in 2001, then AGW is false."
I'm simply pointing out that there are no simple yes/no answers like this. The question of whether AGW is valid is something best decided by the IPCC. They are set up for precisely this…
show full comment
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
I don't agree that the trend since 2000 is a problem for the models or AGW. None of the models pretend to predict year-to-year variations in the future. Climate is about 30-year trends.
Have a look at the data: e.g., http://www.woodfortrees.org/plot/gistemp/mean:12 what we see here is a nice linear upward trend since 1960 with some "noise" superimposed. There is nothing remarkable about the period since 2000. There are lots of examples of similar behavior on 10-year timescales in the recent temperature…
show full comment
Nick Kermode
(logged in via email @hotmail.com)
Michael, read the thread. Like your stuff. A valiant attempt at hearding cats mate.
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Checking back in the thread, the first use of "falsify" comes from you where you talk about AGW being a "falsifiable hypothesis". I agree that it isn't a good term.
Regarding the computer models, I think you misunderstand how they work. If the models were simply multi-parameter fits to the historical temperature data, then they would be only a page of code, with perhaps a dozen parameters, and they would fit beautifully.
No, the models are entirely different, they are essentially the laws of physics…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
"AGW is false" is rather vague terminology. We agree, I'm sure, that CO2 is a greenhouse gas and will remain a greenhouse gas no matter what the trend, so I'm not really asking you to say that there is a trend that will show "AGW is false" in those terms. However, a trend of zero (as we have approximately had since the last IPCC forecasts in 2000) means that the 2deg/century is probably overstated - verging on falsification territory, even allowing for short term variability.
What this means is that there is something missing from our climate models and I hope you would agree that this is problematic for the attribution of the majority of the 20th century warming to CO2 and to the demands for policy responses. Obviously how big a problem depends on what we decide the true rate of warming is. That will require new models and new tests.
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
The analogy you draw is rather lovely although it slightly misses the point. You persist in using this expression "falsify AGW", which isn't helpful. Clearly some element of the warming is due to CO2 - it's a greenhouse gas after all. In other words I agree with you that AGW is not some random theory pulled out of thin air. I am, however, less convinced by the models' ability to hindcast. There are so many degrees of freedom in a climate model and so much uncertainty over the feedbacks in particular…
show full comment
Andrew Montford
Blogger (logged in via email @tiscali.co.uk)
I beg your pardon. I will rephrase:
You say I need a "careful study that establishes the expected influence of AGW" and I give you the IPCC report. You say I need then to show that "the climate is changing in a way that is substantially different" to expectation. I agree with you.
Then you say that even if the climate is changing in a way that is significantly different from expectation you will not tell me whether you accept it as problematic for the AGW hypothesis or not??!! Are you serious?
Maurizio Morabito
(logged in via LinkedIn)
"if the climate began to diverge significantly from the output of the models +/- natural variability"
Sounds like a convoluted way to say "never!"
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Maurizio,
What do you think would happen if the climate diverged from the model output?
In the bizarro world of the denialists the scientists would try to cover up the difference by either adjusting a hidden parameter in the models, or fudging the data, or perhaps just lying about it.
What would actually happen is that there would be a race amongst the various modeling groups around the world to identify the cause of the problem. The winners would be able to write an important paper on it, perhaps…
show full comment
Maurizio Morabito
(logged in via LinkedIn)
Michael - could you please provide some examples that could be interpreted as "the climate has begun to diverge significantly from the output of the models +/- natural variability"?
Methinks even a 5C yearly plunge in global temperature could be considered some sort of "natural variability".
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Here is an example from March this year: "Global radiative forcing from contrail cirrus" by Burkhardt and Karcher, published in Nature Climate Change, 1, 54-58 (2011).
In that paper the authors discuss how they added a new module (called CCMod) to an existing global climate model (ECHAM4) to include the effects of contrails from aircraft. The new code was developed after looking at observational data from 2005 which showed significant cirrus from aircraft that was not taken into account in existing…
show full comment
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
Maurizio, there are limits to "natural variability" that can be estimated through more and more accurate physical models. So when climate scientists compare the output of their models with observations, they look for discrepancies that are greater than can be accounted for by natural variability. So I don't understand why you think that such a discrepancy can never arise. Are you saying that the models are perfect and can't be improved? Or are you saying that any discrepancy will be swept under…
show full comment
Michael Ashley
(Professor of Astrophysics at University of New South Wales)
The bottom line is that AGW has already been proven beyond a shadow of a doubt. If by some extraordinary turn of events it is actually incorrect, then it will become clear when observations diverge from the models. Scientists will then come up with new theories and models to better explain the observations.
So, it is certainly theoretically possible that AGW will be proven incorrect in the future. However, the chance of this happening is about the same as proving that gravity doesn't affect a falling leaf. It just isn't going to happen.
Maurizio Morabito
(logged in via LinkedIn)
oh boy oh boy oh boy...10 out of 10 for sincerity but minus several millions for adhering to science. Not sure if I would recommend reading the IPCC AR4, or perhaps Galileo's "Dialogue concerning the two chief world systems". good luck!
Maurizio Morabito
(logged in via LinkedIn)
What I am saying is that as things stand it is impossible for a "discrepancy" to arise that people won't be able to explain (or rationalize) by appealing to new models, or to natural variability (think Younger Dryas). So there is no way to get out (=falsify) AGW by looking at "models+natural variability".
Maurizio Morabito
(logged in via LinkedIn)
Michael - You have replied to "what happens if observations suggest improvements to the models?". That is not my question. My question relates to your earlier statement, "if the climate began to diverge significantly from the output of the models +/- natural variability, then this would be a cause for concern". I still cannot see how that is ever going to happen.
Even if no model were available for improvement, one could still argue "it's natural variability" and proceed as if nothing happened.
As for AGW being "nonsense" I am not sure where I have said that, so I guess your thought experiment does not apply.