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Bending low with Bated breath

Filed under: — gavin @ 22 December 2018

“Shall I bend low and in a bondman’s key,
With bated breath and whisp’ring humbleness…?”

Shylock (Merchant of Venice, Act 1, Scene 3)

As dark nights draw in, the venerable contrarians at the GWPF are still up late commissioning silly pseudo-rebuttals to mainstream science. The latest, [but see update below] which no-one was awaiting with any kind of breath, is by Dr. Ray Bates (rtd.) which purports to be a take-down of the recent #SR15 report. As Peter Thorne (an IPCC author) correctly noted, this report is a “cut-and-paste of long-debunked arguments”. I’ve grown a little weary of diving down to rebut every repetitive piece of nonsense, but this one has a few funny aspects that make it worthwhile to do so.

When they go low, we go “sigh…”.

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Curve-fitting and natural cycles: The best part


It is not every day that I come across a scientific publication that so totally goes against my perception of what science is all about. Humlum et al., 2011 present a study in the journal Global and Planetary Change, claiming that most of the temperature changes that we have seen so far are due to natural cycles.

They claim to present a new technique to identify the character of natural climate variations, and from this, to produce a testable forecast of future climate. They project that

the observed late 20th century warming in Svalbard is not going to continue for the next 20–25 years. Instead the period of warming may be followed by variable, but generally not higher temperatures for at least the next 20–25 years.

However, their claims of novelty are overblown, and their projection is demonstrably unsound.

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References

  1. O. Humlum, J. Solheim, and K. Stordahl, "Identifying natural contributions to late Holocene climate change", Global and Planetary Change, vol. 79, pp. 145-156, 2011. http://dx.doi.org/10.1016/j.gloplacha.2011.09.005

An exercise about meaningful numbers: examples from celestial “attribution studies”

Filed under: — rasmus @ 30 August 2011

Is the number 2.14159 (here rounded off to 5 decimal points) a fundamentally meaningful one? Add one, and you get

π = 3.14159 = 2.14159 + 1.

Of course, π is a fundamentally meaningful number, but you can split up this number in infinite ways, as in the example above, and most of the different terms have no fundamental meaning. They are just numbers.

But what does this have to do with climate? My interpretation of Daniel Bedford’s paper in Journal of Geography, is that such demonstrations may provide a useful teaching tool for climate science. He uses the phrase ‘agnotology’, which is “the study of how and why we do not know things”.

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Unfinished Business

Filed under: — gavin @ 1 June 2011

A paper in the scientific literature has to have some minimum level of content to be worth publishing (and regrettably, the search for the ‘Least Publishable Unit’ (LPU) of work is occasionally apparent for those wishing to pad their CVs). But what happens when someone has something worth saying that falls below that level? This is might be an update to an earlier paper, with modifications to figure, one extra sensitivity test, or some other minor addition, that could be of interest to readers of the original, but it doesn’t really get to the point where one would write a whole new paper. Some new journals (such as Geoscientific Model Development, GMD) have set up mechanisms to provide versioning of papers so that small updates can be made relatively easily, but this is rather uncommon.

A common reason to want to add additional material is in the light of subsequent commentary. In the usual case of an official submitted comment, the required response provides a good opportunity to give further details, add justification, or even agree with the comment (this last one doesn’t happen very often, but it does occur). Comments are often hard to publish for all sorts of non-scientific reasons, see Rick Trebino’s appalling story for instance, and note GRL’s 2010 decision to stop accepting comments altogether. Unfortunately not all comment/response pairs that do get published are worthwhile, but I still think they can be useful.

Where criticism occurs on a blog, there is no necessity to respond (as there would be for a submitted comment), but it is possible that there is something worth addressing (not everything is of course). Responses posted to that material – either in blog comments or in other blogs are however a little unsatisfying since the blog commentary and response are not tied to the actual paper (though mechanisms like that used by ‘Research Blogging‘ or JournalTalk could conceivably be used), and can quite frequently spiral out of control (with additional criticisms, responses, and often vast amounts of irrelevant commentary). As a useful archive of a discussion, this leaves much to be desired, nonetheless, the determined reader can usually find some nuggets.

But there is a third case where the comment/response effectively never sees the light of day. For a number of reasons critics will sometimes decide not to submit a comment, but rather a whole new paper. This might be because they want to include more information than a comment would allow or are making a comment on a previous work as part of a larger paper. Or it might be that they (correctly) note that comments are not as useful on the CV as a ‘proper’ paper, or indeed, a journal does not want to accept a comment for some reason. Less nobly, comments are sometimes avoided to try to prevent the original authors from having the last word. However, there is a risk that this paper never gets published at all (perhaps because it has less than one LPU, or it isn’t very good, or it clearly nothing more than a comment on a previous paper, or the authors lose enthusiasm). In that case, the criticism, and any response to it from the original authors (if they were asked to respond), simply disappears from sight. While possible, in my experience it is very rare that the critics then turn back to the official comment route.

It is very unusual for any scientific paper to the last word on anything, and there are almost always things that, in retrospect, one would have done differently. So it is not surprising that questions get raised through all this that the original authors might want to tackle without themselves submitting a whole other paper. Theoretically most papers would benefit from a well-refereed post-publication commentary. Yet, without a formal mechanism to shepherd this process, this material generally falls through the cracks.

As readers might have surmised, this is leading up to something.

Two papers that I was an author or co-author on in recent years generated a fair amount of blog commentary – Schmidt (2009) in IJoC and Benestad and Schmidt (2009) in JGR – mostly because they were explorations of issues raised by authors critical of the mainstream view of climate science. Despite the blog discussions, however, in neither case was a comment/response pair published. A comment was submitted on Schmidt (2009) by Jos de Laat, but this did not pass peer review (rightly I think) and no more has been heard of it. In both cases however, other authors whose work was criticised (specifically Ross McKitrick and Nicola Scafetta) submitted new papers to the same journal that were effectively just extended comments. A couple of valid points were made, but much in the draft texts was either wrong or irrelevant. I was asked to respond to both submissions by the editors involved, and did so in the form of a signed draft response as if the papers had indeed been submitted as comments. In both cases however, the papers were eventually rejected. A similar paper by McKitrick and Nierenberg appeared in another journal, while Scafetta’s paper has not been seen again.

So why bring this up now?

The fact is well-crafted comments and responses on both these papers would have been a useful contribution to the literature, and it is a shame that this didn’t happen (as I stated in at least one of the responses). That the authors were unwilling to submit ‘just’ a comment for whatever reason is part of the story (but it is not clear that any actual comment would have stuck to the points I thought worth making, or that the comment/response would have passed peer review either). But both papers have been mentioned recently in various contexts and it was apparent that the conversations might have been at least a little more interesting if the at least some of the unpublished correspondence on the papers had been available.

It strikes me that these are unlikely to be unique circumstances (or at least I would be very surprised if this kind of thing hasn’t happened to other people). So is there interest in RC providing space for these kinds of discussions? Authors, with something extra to say that they don’t ever think they’ll put in a new paper, could add some extra analysis and tie up some of the loose ends. I’d be happy to start the ball rolling by dealing with some issues relating to the papers mentioned above, but is this something else anyone would care to do? Should we instead be advocating for a rapid reaction online journal specifically for worthwhile comments and replies, especially since some journals have stopped accepting them? Thoughts welcome.

The obvious answer

Filed under: — rasmus @ 28 January 2011

Climate science appears to be just like any other science. At least, this is the conclusion from a fresh publication by Marianne Ryghaug and Tomas Moe Skjølsvold (“The global warming of climate science: Climategate and the construction of scientific facts” in International studies in the philosophy of science). This finding is not news to the research community, but this analysis still hints that everything is not as it should be – because why would anyone report from a crime scene if the alleged crime has not even been committed?

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Please, show us your code

Filed under: — rasmus @ 17 December 2009

The 1991 Science paper by Friis-Christensen & Lassen, work by Henrik Svensmark (Physical Review Letters), and calculations done by Scafetta & West (in the journals Geophysical Research Letters, Journal of Geophysical Research, and Physics Today) have inspired the idea that the recent warming is due to changes in the sun, rather than greenhouse gases.

We have discussed these papers before here on RealClimate (here, here, and here), and I think it’s fair to say that these studies have been fairly influential one way or the other. But has anybody ever seen the details of the methods used, or the data? I believe that a full disclosure of their codes and data would really boost the confidence in their work, if they were sound. So if they believe so strongly that their work is solid, why not more transparency?

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Bubkes

Filed under: — gavin @ 26 June 2009 - (Chinese (simplified))

Some parts of the blogosphere, headed up by CEI (“CO2: They call it pollution, we call it life!“), are all a-twitter over an apparently “suppressed” document that supposedly undermines the EPA Endangerment finding about human emissions of carbon dioxide and a basket of other greenhouse gases. Well a draft of this “suppressed” document has been released and we can now all read this allegedly devastating critique of the EPA science. Let’s take a look…

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ACRIM vs PMOD

Filed under: — rasmus @ 6 May 2009 - (Italian)

Two recent papers (Lockwood & Fröhlich, 2008 – ‘LF08’; Scafetta & Willson, 2009 – ‘SW09’) compare the analysis of total solar irradiance (TSI) and the way the TSI measurements are combined to form a long series consisting of data from several satellite missions. The two papers come to completely opposite conclusions regarding the long term trend. So which one (if either) is right, then? And does it really matter?

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Les Chevaliers de l’Ordre de la Terre Plate, Part II: Courtillot’s Geomagnetic Excursion

Filed under: — raypierre @ 18 December 2007 - (Français)

This article continues the critique of writings on climate change by Allègre and Courtillot, started in Part I . If you would like to read either post in French, please click on the flag icon beside the post title above.

Prelude: It’s the physics, stupid

…which of course is a paraphrase of Bill Clinton’s famous quote regarding the economy. We put the last word in small letters since we’ve learned that it is not a good debating technique to imply (even inadvertently) that those who are having trouble seeing the force of our arguments might be stupid. What we wish to emphasize by this paraphrase is the simple fact that the expectation of a causal link between increasing long-lived greenhouse gases (like CO2) and increasing temperature does not rest on some vague, unexplained correlation between 20th century temperature and 20th century greenhouse gas concentration.

The anticipated increase in temperature was predicted long before it was detectable in the atmosphere, indeed long before it was known that atmospheric CO2 really was increasing; it was first predicted by Arrhenius in 1896 using extremely simple radiation balance ideas, and was reproduced using modern radiation physics by Manabe and co-workers in the 1960’s. Neither of these predictions rests on general circulation models, which came in during subsequent decades and made more detailed forecasts possible.

Still, the basic prediction of warming is founded on very fundamental physical principles relating to infrared absorption by greenhouse gases, theory of blackbody radiation, and atmospheric moist thermodynamics. All these individual elements have been verified to high accuracy in laboratory experiments and field observations. For a time, there was some remaining uncertainty about whether water vapor feedback would amplify warming in the way hypothesized in the early energy balance models, but a decade or two of additional observational and theoretical work has shown that there is no real reason to doubt the way in which general circulation models calculate the feedback. When modified by inclusion of the cooling effect of anthropogenic aerosols, the theory gives a satisfactory account of the pattern of 20th and 21st century temperature change.

No other theory based on quantified physical principles has been able to do the same. If somebody comes along and has the bright idea that, say, global warming is caused by phlogiston raining down from the Moon, that does not make everything we know about thermodynamics, infrared absorption, energy balance, and temperature suddenly go away. Rather, it is the job of the phlogiston advocate to quantify the effects of phlogiston on energy balance, and incorporate them in a consistent way beside the existing climate forcings. Virtually all of the attempts to poke holes in the anthropogenic greenhouse theory lose sight of this simple and unassailable principle.

In a paper entitled "Are there connections between the Earth’s magnetic field and climate?" published recently in Earth and Planetary Science Letters, Courtillot and co-authors attempt to cast doubt on carbon dioxide as a primary driver of recent (and presumably future) climate change; he argues instead that fluctuations in the Earth’s magnetic field (partly driven by solar variability) have an important and neglected role. Like most work of this genre, it is carried out in an intellectual void — as if everything we know currently about physics of climate had to be set aside in order to make way for one new (or in fact not-so-new) idea. But the problems don’t end there. With the help of a Comment published by Bard and Delaygue (available here at EPSL or here as pdf) , we’ll expose a pattern of suspicious errors and omissions that pervades Courtillot’s paper. Sloppiness and ignorance is by far the most charitable interpretation that can be placed on this pattern.

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Live (almost) from AGU–Dispatch #6

Filed under: — raypierre @ 14 December 2007

Today was the all-Union session on Tipping Points, and several people have asked for comments on what went on there. I suppose this session might have been useful for people who had to miss the more detailed discussion in specialized sections, but I don’t have much to say about most of the talks, since they for the most part went over issues like ice sheet dynamics and rapid arctic sea ice loss, which I’ve discussed in earlier dispatches. Myself, I never found the notion of “tipping points” to be a very useful contribution to public discourse. The concept is ill-defined and very prone to be misunderstood — as in: we’ve passed a tipping point so it’s too late to do anything (might as well have a party). In Hansen’s talk, he did try to clarify what he meant by a tipping point. His notion of this has less to do with what mathematicians understand as “bifurcations,” and more to do with a kind of inertia in the climate system. He means things like having passed a threshold of CO2 which, given warming in the pipeline and the lifetime of CO2, commits a certain discrete event — e.g. loss of perennial sea ice or the Amazon rainforest– to occurring even if we were to later reduce emissions to zero. He tried to distinguish between reversible and irreversible tipping points. The talk was good cheerleading, after a fashion, but rather thin on real examples of what might be a tipping point in his definition. Everything he said was true (especially the emphasis on the importance of a rapid phase-out of coal burning) but the talk had much more to do with energy policy and lamentation of the power of entrenched fossil fuel interests than it had to do with climate science.
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