David Appell has picked up my comments on his comments on peer review. To recap somewhat, David suggested that McIntyre's findings on Yamal should not be taken seriously because they are not peer reviewed. I pointed out that Einstein and Watson and Crick were not peer reviewed either, to which David has now responded
Steve McIntyre isn't Einstein. Enough said.
In technical terms, this is what is known as a "straw man". The point at issue was whether Steve McIntyre should be taken seriously, not whether he is Einstein.
Given that David has not disputed that Einstein, Watson and Crick were not peer reviewed, I think we can probably now agree that peer review is not a suitable criterion for deciding if an idea should be taken seriously.
David then goes on to say that Einstein, Watson and Crick were published in the best journals of their day. This is a better point, but I think it's hardly persuasive. If the papers passed the review of an editor instead of a pair of peer reviewers, what does that amount to other than another kind of peer review?
Lucia makes some pertinent comments on the need for peer review today too:
...these communications about published papers happen in both formal and informal settings. Historically, no one has said, “Oh. But who cares about Prof. X’s opinion about paper B. He only said it in a conversation at a conference. Until he writes a journal article, I’m not going to pay attention to that opinion."
And besides, if we should ignore McIntyre's comments because they are not published in a journal, hasn't David shot himself in the foot by quoting, in his very next post, the responses of Briffa and the Real Climate team, none of which were (a) peer reviewed or (b) published in a journal?
Let's first remind ourselves of the guts of McIntyre's argument. This is that Briffa had an very small set of tree ring cores in the latter years of his Yamal series and that when you removed this and replaced it with a somewhat larger set of data from the same region, the uptick in the hockey stick shape disappeared. Therefore Briffa's results weren't robust.
Now we'll look at Briffa's response.
Firstly he says McIntyre is implying that he, Briffa, cherrypicked uptrending series so as to get a hockey stick. In reply, McIntyre quotes what he said in his early post:
It is highly possible and even probable that [Briffa's] selection is derived from a prior selection of old trees described in Hantemirov and Shiyatov 2002...
and also a comment he made on another of the Yamal posts
It is not my belief that Briffa crudely cherry picked.
This seems to refute Briffa's accusation that McIntyre was implying malfeasance.
From a scientific perspective, this part of the debate has moved us forward slightly, in that Briffa has now confirmed that the selection of the 12 cores from the much larger population available was due to the Russians. What the reason was for their only using 12 cores remains a mystery. Briffa's response has, however, opened up a new part of the debate that I've not touched on before - this concerns standardisation of the raw tree ring data.
During its lifetime, a tree does not grow at a uniform pace. Tree rings are generally wider when a tree is young than when it is older. If you are using a set of tree rings in climatology, therefore, unless you do something about it, your "treemometer" would always show declining temperatures, regardless of what is going on in the outside world. Standardisation is the process by which this fix is applied, and it involves removing a kind of "average growth curve" from the record to adjust for these changes in growth rate. There are various ways of doing this, the details of which are beyond my ken, but as I understand it, the Russians used the "corridor" method. This works well when you have small numbers of tree cores so it was presumably a suitable choice.
The problem with the corridor method is that it tends to obscure long-term trends in the data, which is precisely what you're interested in when you are doing paleoclimate work. Because of this, when Briffa picked up the seventeen cores for use in his version of Yamal, he applied a different standardisation procedure called RCS, which is better suited to the retention of long-term information.
My application of [RCS] to these same data was intended to better represent the [long-term] growth variations ... to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.
This is problematic. RCS is not suited to dealing with small numbers of cores (I recall reading somewhere that it is not considered suitable with less than 50, but I'm not swearing to that). I also wonder about the nature of Briffa's paper. It strikes me that if the purpose was to "provide a direct comparison with the chronology produced by Hantemirov and Shiyatov", then there can be no arguing with the use of the same data. However, review of Briffa's original paper from 2000 suggests that intercomparison of standardisation methods was not part of his purpose at the time. The paper is a review of developments in paleoclimate and the calculation of a new temperature reconstruction using some of the new data. This being the case, the logical thing to do would surely to have used as much data as possible.
Briffa's other concerns are with McIntyre's sensitivity test - replacing the 12 Briffa cores with the Schweingruber 34 - different cores taken from the same area. This is how he puts it:
The basis for McIntyre's selection of which of our ... data to exclude and which to use in replacement is not clear... He offers no justification for excluding the original data.
McIntyre's comeback on this is that he was very clear about the reasons for excluding the Briffa 12, namely that the number of cores was small. He wanted to test the robustness of the answer by swapping in a larger dataset that had not been used by Briffa.
As well as seeing what happened when the Briffa 12 were swapped for the Schweingruber 34, McIntyre also did a slightly different calculation to see what would happen when both were put in the mix. Briffa says that when McIntyre did this, he underweighted the 12 (i.e. making the loss of hockey stick shape more marked than it should have been). McIntyre has pointed out that Briffa has equally underweighted the Schweingruber 34 by not using them at all, and that debate about the weights doesn't affect the main point, which is that using the Schweingruber 34 makes the hockey stick shape disappear.
Whether the McIntyre version is any more robust a representation of regional tree growth in Yamal than my original, remains to be established.
This one has been doing the rounds for years. McIntyre has been clear from the start that he is not creating an alternative reconstruction. He is testing "official" studies for robustness.
I'm grateful to a reader for pointing out a preliminary response to the Yamal affair from Keith Briffa.
I'm up to my neck in work, so I've only glanced at it so far. The fact of the response is good though - the two sides of the debate need to engage and science will be the winner when they do.
I'll try to comment further tonight.
David Appell, a blogger who has followed the Climate Audit story from the start, but from a different perspective to most readers here, says that some people "on the science side" are looking at what McIntyre has to say.
Which sounds good, because that's the way science works.
David also takes aim at Climate Audit's not being peer reviewed. I think this argument is completely overdone. Watson and Crick weren't peer reviewed. Einstein wasn't either. Didn't stop them being right.
Interestingly, David also tells us to look out for November's Scientific American. Sounds interesting.
Media reaction to the Yamal story has been rather limited so far. I'm not sure whether this is because people are trying to digest what it means or whether it's "too hot to handle". Here's some of the stories I've come across:
James Delingpole (Daily Telegraph blog) How the global warming industry is based on one massive lie.
Chris Horner (National Review online) Mann-made warming confirmed
Andrew Orlowski (The Register) Treemometers: a new scientific scandal.
Tom Fuller (San Francisco Examiner) New data questions claims of accelerated warming
None of the global warming supporters in the mainstream media have gone near it. The reaction of the Guardian - to delete any mention of the affair from their comment threads - has been extraordinary. Even bloggers from the other side of the argument won't go near it. The only exception seems to be the legendary Jo Abbess. James Delingpole is most definitely misguided.
There is a great deal of excitement among climate sceptics over Steve McIntyre's recent posting on Yamal. Several people have asked me to do a layman's guide to the story in the manner of Caspar and the Jesus paper. Here it is.
The story of Michael Mann's Hockey Stick reconstruction, its statistical bias and the influence of the bristlecone pines is well known. McIntyre's research into the other reconstructions has received less publicity, however. The story of the Yamal chronology may change that.
The bristlecone pines that created the shape of the Hockey Stick graph are used in nearly every millennial temperature reconstruction around today, but there are also a handful of other tree ring series that are nearly as common and just as influential on the results. Back at the start of McIntyre's research into the area of paleoclimate, one of the most significant of these was called Polar Urals, a chronology first published by Keith Briffa of the Climate Research Unit (CRU) at the University of East Anglia. At the time, it was used in pretty much every temperature reconstruction around. In his paper, Briffa made the startling claim that the coldest year of the millennium was AD 1032, a statement that, if true, would have completely overturned the idea of the Medieval Warm Period. It is not hard to see why paleoclimatologists found the series so alluring.
Some of McIntyre's research into Polar Urals deserves a story in its own right, but it is one that will have to wait for another day. We can pick up the narrative again in 2005, when McIntyre discovered that an update to the Polar Urals series had been collected in 1999. Through a contact he was able to obtain a copy of the revised series. Remarkably, in the update the eleventh century appeared to be much warmer than in the original - in fact it was higher even than the twentieth century. This must have been a severe blow to paleoclimatologists, a supposition that is borne out by what happened next, or rather what didn't: the update to the Polar Urals was not published, it was not archived and it was almost never seen again.
With Polar Urals now unusable, paleclimatologists had a pressing need for a hockey stick shaped replacement and a solution appeared in the nick of time in the shape of a series from the nearby location of Yamal.
The Yamal data had been collected by a pair of Russian scientists, Hantemirov and Shiyatov, and was published in 2002. In their version of the data, Yamal had little by way of a twentieth century trend. Strangely though, Briffa's version, which had made it into print before even the Russians', was somewhat different. While it was very similar to the Russians' version for most of the length of the record, Briffa's verison had a sharp uptick at the end of the twentieth century -- another hockey stick, made almost to order to meet the requirements of the paleoclimate community. Certainly, after its first appearance in Briffa's 2000 paper in Quaternary Science Reviews, this version of Yamal was seized upon by climatologists, appearing again and again in temperature reconstructions; it became virtually ubiquitous in the field: apart from Briffa 2000, it also contributed to the reconstructions in Mann and Jones 2003, Jones and Mann 2004, Moberg et al 2005, D'Arrigo et al 2006, Osborn and Briffa 2006 and Hegerl et al 2007, among others.
When McIntyre started to look at the Osborn and Briffa paper in 2006, he quickly ran into the problem of the Yamal chronology: he needed to understand exactly how the difference between the Briffa and Hantemirov versions of Yamal had arisen. McIntyre therefore wrote to the Englishman asking for the original tree ring measurements involved. When Briffa refused, McIntyre wrote to Science, who had published the new paper, pointing out that, since it was now six years since Briffa had originally published his version of the chronology, there could be no reason for withholding the underlying data. After some deliberation, the editors at Science declined the request, deciding that Briffa did not have to publish anything more as he had merely re-used data from an earlier study. McIntyre should, they advised, approach the author of the earlier study, that author being, of course, Briffa himself. Wearily, McIntyre wrote to Briffa again, this time in his capacity as author of the original study in Quaternary Science Reviews and he was, as expected, turned down flat.
That was how the the investigation of the Yamal series stood for the next two years until, in July 2008, a new Briffa paper appeared in the pages of the Philosophical Transactions of the Royal Society B, the Royal Society's journal for the biological sciences. The new paper discussed five Eurasian tree ring datasets, which, in fairly standard Hockey Team fashion, were unarchived and therefore not succeptible to detailed analysis. Among these five were Yamal and the equally notorious Tornetrask chronology. McIntyre observed that the only series with a strikingly anomolous twentieth century was Yamal. It was frustratingly therefore that he had still not managed to obtain Briffa's measurement data. It appeared that he was going to hit another dead end. However, in the comments to his article on the new paper, a possible way forward presented itself. A reader pointed out that the Royal Society had what appeared to be a fairly clear and robust policy on data availability:
As a condition of acceptance authors agree to honour any reasonable request by other researchers for materials, methods, or data necessary to verify the conclusion of the article...Supplementary data up to 10 Mb is placed on the Society's website free of charge and is publicly accessible. Large datasets must be deposited in a recognised public domain database by the author prior to submission. The accession number should be provided for inclusion in the published article.
Having had his requests rejected by every other journal he had approached, McIntyre had no great expectations that the Royal Society would be any different, but there was no harm in trying and he duly sent off an email pointing out that Briffa had failed to meet the Society's requirement of archiving his data prior to submission and that the editors had failed to check that Briffa had done so. The reply, to McIntyre's surprise, was very encouraging:
We take matters like this very seriously and I am sorry that this was not picked up in the publishing process.
Was the Royal Society, in a striking contrast to every other journal in the field, about to enforce its own data availability policy? Had Briffa made a fatal mistake?
Summer gave way to autumn and as October drew to a close, McIntyre had still heard nothing from the Royal Society. However, in response to some further enquiries, the journal sent McIntyre some more encouraging news -- Briffa would be producing most of his data, although not immediately. Most of it would be available by the end of the year, with the remainder to follow in early 2009.
The first batch of data appeared on schedule in the dying days of 2008 and it was something of a disappointment. The Yamal data, as might have been expected, was to be archived with the second batch, so there would be a further delay before the real action could start. Meanwhile, however, McIntyre could begin to look at what Briffa had done elsewhere. It was not to be plain sailing. For a start, Briffa had archived data in an obsolete data format, last used in the era of punch-cards. This was inconvenient, and apparently deliberately so, but it was not an insurmountable problem -- with a little work, McIntyre was able to move ahead with his analysis. Briffa had also thrown a rather larger spanner in the works though: while he had archived the tree ring measurements, he had not supplied any metadata to go with it -- in other words there was no information about where the measurements had come from. All there was was a tree number and the measurements that went with it. However, McIntyre was well used to this kind of behaviour from climatologists and he had some techniques at hand for filling in some of the gaps. Climate Audit postings on the findings followed in fairly short order, some of which were quite intriguing. There was, however, no smoking gun.
There followed a long hiatus, with no word from the Royal Society or from Briffa. McIntyre would occasionally visit Briffa's web page at the CRU website to see if anything new had appeared, but to no avail. Eventually, though, Briffa's hand was forced, and in late September 2009, a reader pointed out to McIntyre that the remaining data was now available. It had been quietly posted to Briffa's webpage, without announcement or the courtesy of an email to Mcintyre. It was nearly ten years since the initial publication of Yamal and three years since McIntyre had requested the measurement data from Briffa. Now at last some of the questions could be answered.
When McIntyre started to look at the numbers it was clear that there were going to be the usual problems with a lack of metadata, but there was more than just this. In typical climate science fashion, just scratching at the surface of the Briffa archive raised as many questions as it answered. Why did Briffa only have half the number of cores covering the Medieval Warm Period that the Russian had reported? And why were there so few cores in Briffa's twentieth century? By 1988 there were only 12 cores used, an amazingly small number in what should have been the part of the record when it was easiest to obtain data. By 1990 the count was only ten, dropping still further to just five in 1995. Without an explanation of how the selection of this sample of the available data had been performed, the suspicion of `cherrypicking' would linger over the study, although it is true to say that Hantemirov also had very few cores in the equivalent period, so it is possible that this selection had been due to the Russian and not Briffa.
The lack of twentieth century data was still more remarkable when the Yamal chronology was compared to the Polar Urals series, to which it was now apparently preferred. The ten or twelve cores used in Yamal was around half the number available at Polar Urals, which should presumably therefore have been considered the more reliable. Why then had climatologists almost all preferred to use Yamal? Could it be because it had a hockey stick shape?
None of these questions was likely to be answered without an answer to the question of which trees came from which locations. Hantemirov had made it clear in his paper that the data had been collected over a wide area - Yamal was an expanse of river valleys rather than a single location. Knowing exactly which trees came from where might well throw some light onto the question of why Briffa's reconstruction had a hockey stick shape but Hantemirov's didn't.
As so often in McIntyre's work, the clue that unlocked the mystery came from a rather unexpected source. At the same time as archiving the Yamal data, Briffa had recorded the numbers for another site discussed in his Royal Society paper: Taimyr. Taimyr had, like Yamal, also emerged in Briffa's Quaternary Science Reviews paper in 2000. However, in the Royal Society paper, Briffa had made major changes, merging Taimyr with another site, Bol'shoi Avam, located no less than 400 kilometres away. While the original Taimyr site had something of a divergence problem, with narrowing ring widths implying cooler temperatures, the new composite site of Avam--Taimyr had a rather warmer twentieth century and a cooler Medieval Warm Period. The effect of this curious blending of datasets was therefore, as so often with paleoclimate adjustments, to produce a warming trend. This however, was not what was interesting McIntyre. What was odd about Avam--Taimyr was that the series seemed to have more tree cores recorded than had been reported in the two papers on which it was based. So it looked as if something else had been merged in as well. But what?
With no metadata archived for Avam-Taimyr either, McIntyre had another puzzle to occupy him, but in fact the results were quick to emerge. The Avam data was collected in 2003, but Taimyr only had numbers going up to 1996. Similarly, the Taimyr trees were older, with dates going back to the ninth century. It was therefore possible to make a tentative split of the data by dividing the cores into those finishing after 2000 and those finishing before. This was a good first cut, but the approach assigned 107 cores to Avam, which was more than reported in the original paper. This seemed to confirm the impression that there was something else in the dataset.
At the same time, McIntyre's rough cut approach assigned 103 cores to Taimyr, a number which meant that there were still over 100 cores still unallocated. The only way to resolve this conundrum was by a brute force technique of comparing the tree identification numbers in the dataset to tree ring data in the archives. In this way, McIntyre was finally able to work out the provenance of at least some of the data.
Forty-two of the cores turned out to be from a location called Balschaya Kamenka, some 400 km from Taimyr. The data had been collected by the Swiss researcher, Fritz Schweingruber. The fact that the use of Schweingruber's data had not been reported by Briffa was odd in itself, but what intrigued McIntyre was why Briffa had used Balschaya Kamenka and not any of the other Schweingruber sites in the area. Several of these were much closer to Taimyr -- Aykali River was one example, and another, Novaja Rieja, was almost next door.
By this point then, McIntyre knew that Briffa's version of Yamal was very short of twentieth century data, having used just a selection of the available cores, although the grounds on which this selection had been made was not clear. It was also obvious that there was a great deal of alternative data available from the region, Briffa having been happy to supplement Taimyr with data from other locations such as Avam and Balschaya Kamenka. Why then had he not supplemented Yamal in a similar way, in order to bring the number of cores up to an acceptable level?
The reasoning behind Briffa's subsample selection may have been a mystery, but with the other information McIntyre had gleaned, it was still possible to perform some tests on its validity. This could be done by performing a simple sensitivity test, replacing the twelve cores that Briffa had used for the modern sections of Yamal with some of the other available data. Sure enough, there was a suitable Schweingruber series called Khadyta River close by to Yamal, and with 34 cores, it represented a much more reliable basis for reconstructing temperatures.
McIntyre therefore prepared a revised dataset, replacing Briffa's selected 12 cores with the 34 from Khadyta River. The revised chronology was simply staggering. The sharp uptick in the series at the end of the twentieth century had vanished, leaving a twentieth century apparently without a significant trend. The blade of the Yamal hockey stick, used in so many of those temperature reconstructions that the IPCC said validated Michael Mann's work, was gone.
[Updated 30/9/09 to correct minor dating issue. Also removed the reference to KB's illness which is apparently genuine]
James Bartholemew has an interesting post about a trip he made to hear about the new A' Level in French.
I was told that not one of the examining boards for French 'A' level now sets a single piece of French literature. The students will not read a single French book or play. Instead they will go through a textbook which includes one chapter on literature and three on the environment. This is a sick cocktail of philistinism and eco-propaganda.
By coincidence, I was also in school this week to hear about a new curriculum - this time the "Curriculum for Excellence" (CfE), which will be the basis of my children's education. On the morning before the talk, I chanced upon a post by Shuggy, who teaches at secondary level in Glasgow. He was, shall we say, not the best possible advertisement for CfE, describing it as "nebulous cack", so when I rolled up at the local primary I was fully prepared to be underwhelmed by the experience.
But it's fair to say that even with Shuggy's imprecations, I was still taken aback by the full fatuousness of the experience and the sheer vacuity of what my children will learn. Educational bureaucrats may think it impressive to emphasize the "journey" on which they are embarking and the "dialogues" in which they are going to engage young people, but to anyone who lives outside this rarified atmosphere, it just sounds like mumbo-jumbo.
A "high-quality, values-based education" sounds interesting - promising even - until one asks "whose values?". What do they mean when they say they want to "prepare children for living in the global community"? Or when they stress the importance of "developing political sensitivity" (I kid you not)?
To a bureaucrat, the truth, if it must be told, has to be attended by a bodyguard of nebulous cack, but even through the fog of kafkaspeak, this sounded rather ominous. And later, it became rather clearer that, as I had feared, the values they were going to be teaching were not even close to mine. In a slide about "21st century learning", we heard about the concepts around which education is now to be based:
- Sustainable living education
- Health-promoting schools
- International education
- Global citizenship
- Enterprise in education
If this wasn't horrifying enough, I spent the coffee break looking at the sample text books helpfully provided for the occasion. The subject matter was pretty much predictable - climate change, more climate change, recycling, fair trade and then more climate change.
Every cloud has a silver lining though. My children have learned from an early age that not everything they hear from people in a position of authority is right. That's an important lesson.
Here is the council of NERC, the main body for funding climate science in the UK:
Mr Edmund Wallis
Professor Alan Thorpe
Chief Executive, and Deputy Chairman
Professor Paul Curran
Vice Chancellor and Professor of Physical Geography, Bournemouth University
Professor Huw Davies
Institute for Atmospheric & Climate Science, ETH
Mr Rowan Douglas
Managing Director, Willis Analytics for Willis Re
Professor Alastair Fitter
Department of Biology, University of York
Professor Anne Glover
Chief Scientific Adviser for Scotland
Professor Charles Godfray
Professor of Zoology, University of Oxford
Professor Alex Halliday
University of Oxford
Mr Peter Hazell
Chairman of the Argent Group and non-executive director of various UK plcs
Professor Michael Lockwood
Professor of Space Plasma Physics, and Energy and the Environment, University of Southampton; Chief Scientist, Space Science Department, Rutherford Appleton Laboratory
Professor Thomas Meagher
Professor and Chair of Plant Biology at the University of St Andrews
Professor Julia Slingo OBE
Chief Scientist Met Office
Professor Andrew Watson
Professor at the School of Environmental Sciences, University of East Anglia
Professor Robert (Bob) Watson
Chief Scientific Advisor to DEFRA
Professor Marjorie Wilson
Professor at the Institute of Geophysics, School of Earth and Environment and Pro-Dean for Research in the Faculty of Environment, University of Leeds
There sure are a lot of names I recognise in that list - Lockwood and Bob Watson are certified alarmists for sure. If I recall correctly, Slingo is one too. Andrew Watson was involved in the Royal Society geoengineering report, so it's fairly clear which side of the fence he's on. Interesting also to see someone from the insurance industry on the list. This is a theme that Climate Resistance has picked up on from time to time - insurers are able to put their rates up in expectation of increased losses from global warming.
Interesting fact: the Chairman of the Met Office board, Robert Napier, is or has been:
- Chairman of the Green Fiscal Trust*
- Chairman of the trustees of the World Centre of Monitoring of Conservation
- a director of the Carbon Disclosure Project
- a director of the Carbon Group
- Chief executive of the World Wildlife Fund UK
He is also a member of the Green Alliance.
If we are supposed to reject the views of scientists, like Richard Lindzen, on the grounds that they have given speeches at thinktanks that have accepted money from oil interests, then I think its fair to say that we can safely discount anything said by the Met Office forthwith.
*This is per the source. It should actually read "Green Fiscal Commission".
Well, yes, we did say that the people shouldn't be frightened of the state and the state should be frightened of its people. But guys, we didn't mean you had to be frightened of small children too.
The Department of Children, Schools and Families have recently written to the Information Commissioner stating that they are having difficulties in complying with requests from home educators. (You will remember that the government launched an inquiry into HE which concluded that it was unregulated and was therefore bad). Confronted by an array of FoI requests, the DCSF now claim that there has been "harassment and a display of hostility towards Mr Graham Badman", the civil servant who was appointed to head the inquiry. They say that they need to consider the implications of this behaviour for their interpretation of Section 38 of the FoI Act, which "applies to information that if disclosed would be likely to put the physical or mental health or the safety of any individual at risk or greater risk". In other words they want to withhold information because its release might upset Mr Badman.
DCSF staff have helpfully provided some examples of some of this harassment and hostility. Here's one. It's strong stuff, so I've put it below the fold for the benefit of the squeamish...
Environmentalists are keen to write off anyone whose research has been anywhere near oil money or coal money (or probably a banker too). It's very silly. I remember one group of greens condemning Climate Audit's Steve McIntyre because he had once written a paper for a think tank that had once accepted a donation from Exxon.
It's that daft.
Anyway, from the same Nature article I covered in the last piece comes this:
We're entering a new epoch of sea-ice melt in the Arctic Ocean due to climate change," says Peter Wadhams, an oceanographer at the University of Cambridge, UK, who is conducting research in the Fram Strait off Greenland aboard the Greenpeace ship Arctic Sunrise.
Scientist cosy with environmentalists? I think we can safely ignore everything Peter Wadhams produces from now on.
Quirin Schiermeier, writing at Nature, says that the refreeze has started in the Arctic.
Arctic sea ice has declined slightly less dramatically this year than in the past couple of years.
This is possibly the most outrageous piece of nonsense I've read since the disinformation by the mainstream media about the North-East passage last week. At least the mainstream media has the excuse that it's staffed by the intellectually challenged. But Nature is supposed to be the world's premier scientific journal. You would struggle to describe it as even reputable after this. It's positively Orwellian.
Arctic sea ice has gone up this year. A lot. It went up the year before a lot too. How Dr Schiermeier can make the statement he did is beyond me.
So, now we know which way the ice is heading at present, what does it mean?
Dwindling summertime sea-ice extent is a prime indicator of climate change at high northern latitudes.
Good, so rising summertime sea-ice would suggest that things are getting colder at the moment?
No sign that long-term trend is reversing, scientists caution.
Huh? What would a sign of the long-term trend reversing look like then?