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Global Warming Since 1997 Underestimated by Half

Filed under: — stefan @ 13 November 2013

A new study by British and Canadian researchers shows that the global temperature rise of the past 15 years has been greatly underestimated. The reason is the data gaps in the weather station network, especially in the Arctic. If you fill these data gaps using satellite measurements, the warming trend is more than doubled in the widely used HadCRUT4 data, and the much-discussed “warming pause” has virtually disappeared.

Obtaining the globally averaged temperature from weather station data has a well-known problem: there are some gaps in the data, especially in the polar regions and in parts of Africa. As long as the regions not covered warm up like the rest of the world, that does not change the global temperature curve.

But errors in global temperature trends arise if these areas evolve differently from the global mean. That’s been the case over the last 15 years in the Arctic, which has warmed exceptionally fast, as shown by satellite and reanalysis data and by the massive sea ice loss there. This problem was analysed for the first time by Rasmus in 2008 at RealClimate, and it was later confirmed by other authors in the scientific literature.

The “Arctic hole” is the main reason for the difference between the NASA GISS data and the other two data sets of near-surface temperature, HadCRUT and NOAA. I have always preferred the GISS data because NASA fills the data gaps by interpolation from the edges, which is certainly better than not filling them at all.

A new gap filler

Now Kevin Cowtan (University of York) and Robert Way (University of Ottawa) have developed a new method to fill the data gaps using satellite data.

It sounds obvious and simple, but it’s not. Firstly, the satellites cannot measure the near-surface temperatures but only those overhead at a certain altitude range in the troposphere. And secondly, there are a few question marks about the long-term stability of these measurements (temporal drift).

Cowtan and Way circumvent both problems by using an established geostatistical interpolation method called kriging – but they do not apply it to the temperature data itself (which would be similar to what GISS does), but to the difference between satellite and ground data. So they produce a hybrid temperature field. This consists of the surface data where they exist. But in the data gaps, it consists of satellite data that have been converted to near-surface temperatures, where the difference between the two is determined by a kriging interpolation from the edges. As this is redone for each new month, a possible drift of the satellite data is no longer an issue.

Prerequisite for success is, of course, that this difference is sufficiently smooth, i.e. has no strong small-scale structure. This can be tested on artificially generated data gaps, in places where one knows the actual surface temperature values but holds them back ​​in the calculation. Cowtan and Way perform extensive validation tests, which demonstrate that their hybrid method provides significantly better results than a normal interpolation on the surface data as done by GISS.

The surprising result

Cowtan and Way apply their method to the HadCRUT4 data, which are state-of-the-art except for their treatment of data gaps. For 1997-2012 these data show a relatively small warming trend of only 0.05 °C per decade – which has often been misleadingly called a “warming pause”. The new IPCC report writes:

Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 15 years (1998–2012; 0.05 [–0.05 to +0.15] °C per decade), which begins with a strong El Niño, is smaller than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade).

But after filling the data gaps this trend is 0.12 °C per decade and thus exactly equal to the long-term trend mentioned by the IPCC.


The corrected data (bold lines) are shown in the graph compared to the uncorrected ones (thin lines). The temperatures of the last three years have become a little warmer, the year 1998 a little cooler.

The trend of 0.12 °C is at first surprising, because one would have perhaps expected that the trend after gap filling has a value close to the GISS data, i.e. 0.08 °C per decade. Cowtan and Way also investigated that difference. It is due to the fact that NASA has not yet implemented an improvement of sea surface temperature data which was introduced last year in the HadCRUT data (that was the transition from the HadSST2 the HadSST3 data – the details can be found e.g. here and here). The authors explain this in more detail in their extensive background material. Applying the correction of ocean temperatures to the NASA data, their trend becomes 0.10 °C per decade, very close to the new optimal reconstruction.


The authors write in their introduction:

While short term trends are generally treated with a suitable level of caution by specialists in the field, they feature significantly in the public discourse on climate change.

This is all too true. A media analysis has shown that at least in the U.S., about half of all reports about the new IPCC report mention the issue of a “warming pause”, even though it plays a very minor role in the conclusions of the IPCC. Often the tenor was that the alleged “pause” raises some doubts about global warming and the warnings of the IPCC. We knew about the study of Cowtan & Way for a long time, and in the face of such media reporting it is sometimes not easy for researchers to keep such information to themselves. But I respect the attitude of the authors to only go public with their results once they’ve been published in the scientific literature. This is a good principle that I have followed with my own work as well.

The public debate about the alleged “warming pause” was misguided from the outset, because far too much was read into a cherry-picked short-term trend. Now this debate has become completely baseless, because the trend of the last 15 or 16 years is nothing unusual – even despite the record El Niño year at the beginning of the period. It is still a quarter less than the warming trend since 1980, which is 0.16 °C per decade. But that’s not surprising when one starts with an extreme El Niño and ends with persistent La Niña conditions, and is also running through a particularly deep and prolonged solar minimum in the second half. As we often said, all this is within the usual variability around the long-term global warming trend and no cause for excited over-interpretation.

263 Responses to “Global Warming Since 1997 Underestimated by Half”

  1. 1
    Ray Ladbury says:

    Surprising doesn’t begin to describe this. We’re really talking just about the influence of the Arctic, as the Antarctic hasn’t warmed nearly as much, so we’re talking about 20% of the globe doubling the warming?

  2. 2
    JM says:

    Remarkable, 50% of the global warming has been hiding out in the 16% of the Globe we can’t accurately monitor temperature. Of the 50% increase in warming how much of that was attributed to the Poles and how much from Africa?

    [Response: You have to realise that the adjustment is quite small – within the published uncertainty of the HadCRUT4 data. But a small adjustment can make a big difference to a short-term trend – the emphasis is on short-term here. It is just another illustration that short-term trends like this are not robust, due to natural variability and (as shown here) due to data uncertainty. That is why the IPCC in its SPM quoted above says that the 1998-2012 trend is +0.05 with an uncertainty range of –0.05 to +0.15 °C per decade. The new estimate of Cowtan and Way is within this.
    As we have so often said here: do not over-interpret short-term trends, one way or the other. -stefan]

  3. 3
    Steven Mosher says:

    Robert does awesome work. Thanks for covering this article.

  4. 4
    Walter Pearce says:

    How does this relate to your previous post on ocean warming?

    In other words, is the larger-than-earlier-thought increase in atmospheric temperatures occurring in tandem with the natural variation in ocean uptake during the last decade or so?

  5. 5
    robert says:

    It begs the question: What will the warming be if China and India clean up their aerosol problems? !

  6. 6
    Yvan Dutil says:

    Let me add this: there is no pause. But, we have explanation for the “pause” ranging from reduction in solar activity, increase ocean uptake, CFC curtailment and Chinese aerosol.

    As I understand it, without these factors, the temperature would have rocketed up.

  7. 7
    Doug Bostrom says:


    Presuming this holds up, is there a unit of measurement sufficient to encompass the suddenly humiliating and regretful history of over-heated blather on “the pause?”

    Even if the result were wrong, the paper’s exposure and highlighting of how much empty speculation has been flung around about “the pause” ought to be a permanent, thought-provoking monument to the value of due caution.

  8. 8
    t_p_hamilton says:

    JM said:”Remarkable, 50% of the global warming has been hiding out in the 16% of the Globe we can’t accurately monitor temperature.”

    Not really, if one notices that the additional Temperature data is less extremely varying than areas affected strongly by El Nino and La Nina, and that the arctic warming is rapid.

    “Of the 50% increase in warming how much of that was attributed to the Poles and how much from Africa?” Arctic, I would guess.

  9. 9
    Tom Curtis says:

    Ray Ladbury and JM, the HadCRUT4 lacks data from large areas in Africa, the middle east and Asia (particularly central Asia), in addition to most of the Amazon basin and parts of Australia. This is evident in the figure in the main article. Your supposition that the effect is the result of Arctic data only is, therefore, simply not factual. As it happens, most of the nations that set new all time maximum temperature records in 2010 lie in a region (North Africa, Middle East, Central Asia) with very poor coverage by HadCRUT4, hence the particularly large correction in 2010. More generally, much of the area excluded in HadCRUT4 is not significantly effected by ENSO. That is why HadCRUT4 is more sensitive to ENSO than other surface temperature indices, and a significant factor in why making the index truly global increases the trend significantly.

  10. 10
    Hank Roberts says:

    Hm. We seem to have misplaced the North Pole:

    While there were weather stations much closer to the top of the world, they haven’t been taking data since the 1950s:

    What, all those nuclear submarines, and no data about the conditions? the ice was too thick to push a thermometer through, but a Polaris missile was still feasible?

  11. 11
    Blair Dowden says:

    Dr. Kevin Cowtan ( is a chemist at the University of York specializing in X-ray crystallography. I do not see any hint of a connection with his work to climate change. Robert Way ( is a graduate student in geography at the University of Ottawa, but at least one of his few papers is somewhat relevant. These are not the qualifications I would expect for the authors of such a ground breaking paper. [This comment seemed to get lost, so I am posting it again.]

    [Response: With the amount of open data available for anyone to analyse, this is not such a stretch. There are many good papers from ‘outsiders’ in the literature and in general this kind of constructive input should be welcomed (as with work done by Zeke Hausfather, Troy Masters etc.). – gavin]

    [Response: p.s. It is well worth looking at his impressive citation record. I think it is excellent if top scientists from other fields make methodological contributions to climate science. -stefan]

  12. 12
    Peter Lilley says:

    Why do nearly all data reanalyses on this site show the warming is greater than the raw data?

    [Response: Not true. The raw SST data show much larger trends that turned out to be spurious due to changes in measuring techniques. The GISTEMP analyses correct for an urban heating effect that would otherwise lead to a (slightly) stronger trend globally. Homogeneity corrections at GHCN go both ways. The analysis in this instance is correcting for an obvious hole in the HadCRUT4 data (mainly the Arctic) which even you know has been warming faster. Your question therefore smacks of a desire to have lower trends for reasons that are not clear. I prefer to take the info as it comes rather than wishing it were otherwise. – gavin]

  13. 13
    SCM says:

    I peeked in the paper and it says that most of the ‘hidden’ temperature increase was in the arctic, rather than the antarctic. This would certainly explain why arctic sea ice cover has been absolutely crashing in recent years while the HARDCRU/GISS global average temps had been increasing more modestly.

    I wonder if the Cowtan and Way type temperature calculation will become one of the standard temperature datasets.

  14. 14
    Doug Bostrom says:

    Blair Dowden is obviously good at finding CV information. Is Blair equally as good at reading research papers and finding points of disagreement or agreement?

    Blair’s is a borehole comment if ever there was one. Presumably it was let through only to shame Blair.

    Failing that: Blair, if you look carefully, you’ll see the paper is about global surface temperature trends, not about the life histories of Robert Way and Kevin Cowtan. The material in the paper is entirely separate and distinct from the authors. In fact, it would not matter if the paper had been an accidental product of 1,000 monkeys typing on 1,000 keyboards and only by chance was correct let alone coherent– you’d still need to address the content of the paper, not irrelevant biographical material.

    Can you see the difference between author and research? If you have doubts about the results, read the paper and see if you feel better. You won’t accomplish anything by looking at biographies.

    Pro tip: if you find yourself looking at an author’s choice of hairstyle, birthdate or food preferences, you show the world you’re bankrupt in terms of substantive argument

  15. 15
    theotherstevejobs says:

    Surprising isn’t hardly how i’d label it.

    If 16% of the globe we cant monitor can double the amount of global warming – can you imagine how much warming could be discovered if we had actual data for sea surface air temperatures before satellites?
    Or measured air temps before 1850?

    If my calculations are correct, you could have like four times as much global warming.

  16. 16
    Dave123 says:

    More to the point blair…if you knew enough to know about work on electron density functions in X-ray Crystallography, you’d see the that Cowtan works with contoured, dispersed data sets and its natural to transfer that skill to climate change data sets.

    I’ll point out something else for you: Much of climatology is the work of people with backgrounds in diverse disciplines coming together. People who study “innovation” in both industrial and scientific environments have identified this confluence of talents and perspectives as key to moving fields ahead. Cowtan’s take on things can be seen as one such influence. Your ideas about purity are simply biblical and have nothing to do with the real world of science, academic or industrial.

  17. 17
    Dave123 says:

    Stefan- It would nice to have a few comments from you on how the data as refined by Cowtan and Way affects the work you and Grant did removing ENSO, Volcanic and Solar effects from the temperature trends. Surely you must be well along with that. Any hints?

  18. 18
    edgeofkaos says:

    Curious as to whether there are two Peter Lilleys with an interest in climate change, or whether comment #12 is from the right wing Tory MP, Vice Chairman and Senior Independent Non-Executive Director at Tethys Petroleum, member of the House Of Commons Select Committee on Climate Change (no conflict of interest there, then), and one of only three MPs to vote against the Climate Change Act?

    In that debate Lilley is on record as saying “As we know, the pause that was already well established in 2008 has continued since then. There has been no 0.3° C rise, and all the years since then have been cooler than 1998.”

    Might this be the reason why his question, as gavin puts it, “smacks of a desire to have lower trends for reasons that are not clear”? Just wondering.

    [Response: It appears to be he. – gavin]

  19. 19
    Jerry says:

    In reply to ” The analysis in this instance is correcting for an obvious hole in the HadCRUT4 data (mainly the Arctic) which even you know has been warming faster.”

    Question: there’s a hole in the data, meaning that we don’t know what the temperature is doing. Yet you’re saying people “know” the Arctic has been warming faster.

    How can you know the Arctic is warming faster when there’s a hole in the data? I’m experiencing some hardcore cognitivie dissonance. Isn’t that like saying, “we don’t have any blood tests but you know your cholesterol is through the roof?”

    [Response: Because we have satellite data, sea ice buoys, the obvious decline in sea ice volume/area/extent and information from the stations closest to the Arctic which show some the largest trends on the planet. So, yes, we know. – gavin]

  20. 20
    Blair Dowden says:

    Doug Bostrom and Dave123: Personal attacks are not helpful. I looked up Robert Way only because he lives in my city and I did not know any climate change work was done here. I was surprised he was only a graduate student (his site did not mention he is a PhD student). So I looked up the other author and found he was from outside climate science. I now see “He took on this project in his spare time because the problem has synergies with his previous work and is of significant public interest.”

    I am not qualified to criticize the paper and did not do that. I asked a genuine question about how people from outside the field can discover something missed by the professionals in the field. I have observed most of the attacks on climate science come from outside the field. In general, pseudoscience is usually from outsiders saying the people with careers in the subject are all wrong. Perhaps this has made me overly skeptical of outside contributions. I think it is normal practice to look at the qualification of the authors of a paper. I also think that unusual authors have an obligation to explain why their background is relevant and why they have found something that people in the field have missed. I agree that in the end only the contents of the paper are relevant, and the scientists here seem supportive of it. I was hoping for a comment on where this paper fits in the scientific consensus, and what kind of uncertainties are involved.

  21. 21

    All Blair seems to be saying is that the paper’s authors don’t appear to be climate change experts. I suspect one of the reasons that he brought it up is that the general public, when told there is no debate amongst experts as to whether warming is occurring, are also told that the hundreds of scientists they hear about in the news dismissing warming (or saying that there is a debate) are not climate change experts and therefore shouldn’t be believed.

    So, if I write an article about this in Examiner (which no one reads anyway – ha), what do I say to the commenter who says, “Gee, every time I bring up the name of a “scientist” who disputes warming, I get told he’s not an expert and doesn’t know what he’s talking about, so why should I believe this other non-climate change expert who doesn’t dispute warming? Isn’t that contradictory logic?”

    Isn’t that all Blair is pointing out?

    P.s. I appreciate y’all giving this non-expert (me) a chance to read and post on here.

    [Response: There is a difference between a retired dentist declaring that climate science is all wrong, and outsiders using the huge amount of data now available to make constructive additions to the technical literature. We’ve been encouraging the ‘outsider’ critics to do this for years. But climate science has always had people from different backgrounds making contributions (I was a mathematician originally, Stefan studied general relativity, other colleagues were turbine engineers, geologists, seismologists etc.). The worth of the contributions varies, but this one seems well thought out. – gavin]

  22. 22
  23. 23
    Tim Jones says:

    There’s certainly nothing inconsistent in RealClimate’s take on the “pause.”
    A warming pause?
    “(2) It is highly questionable whether this “pause” is even real. It does show up to some extent (no cooling, but reduced 10-year warming trend) in the Hadley Center data, but it does not show in the GISS data, see Figure 1. There, the past ten 10-year trends (i.e. 1990-1999, 1991-2000 and so on) have all been between 0.17 and 0.34 ºC per decade, close to or above the expected anthropogenic trend, with the most recent one (1999-2008) equal to 0.19 ºC per decade – just as predicted by IPCC as response to anthropogenic forcing.”

    It’s certainly nice to see more specificity than ocean heat content is growing.

    Central Texas’ cedar elm trees are a little worried about the summer of 2014. The last few years of drought haven’t been kind to the woods at all. I’m hoping the 14 inches of rain we got the night before Halloween soaked in enough to get us through the next Texas scorcher.

  24. 24
    Doug Bostrom says:

    Blair, pardon me if I seemed to be over-reactive, but if you follow the topic of climate change for more than a very short while you’ll see that all too often the “argument” of people who disagree with results they don’t like is to mount the ultimate personal attack: they try to substitute comments about an author’s personal background for substantive comment about the author’s work.

    Your comment exactly matched that archetypal footprint.

    I also think that unusual authors have an obligation to explain why their background is relevant and why they have found something that people in the field have missed.

    Again, that’s all irrelevant. The paper in question is published having passed peer review, hence the authors have met their obligations as researchers, the only obligations that immediately pertain. If you then find some issue with the paper that is substantial, your obligation is to follow their example by meticulously articulating a case and then– ideally– getting it published. So, any relevant and useful progress for you can be found in the paper, not in biographical trivia.

  25. 25
    James Cross says:

    I’m a little confused here.

    “Cowtan and Way circumvent both problems by using an established geostatistical interpolation method called kriging – but they do not apply it to the temperature data itself (which would be similar to what GISS does), but to the difference between satellite and ground data. ”

    I didn’t think satellite data covered the arctic or the antarctic but the paper claims that is where the gaps is.

    What’s more the satellite data shows the same pause yet now it is being used to show there is no pause.

    [Response: The UAH satellite data show a pause when you start in 1998, but from 1999 they show a warming of +0.15 °C per decade. If you believe in short-term trends, you must conclude that there was a pause since 1998 but there has been no pause any more already since 1999. The difference of adding 1998 is greater here than with the surface data, because the response of tropospheric temperature to ENSO is twice as large as that of surface temperatures to ENSO (in other words, the 1998 anomaly is much larger in the satellite data).
    But the more basic point here is that the Cowtan paper does not use the satellite time trend (which is somewhat unreliable – remember the long history of corrections, and the difference in trends between the UAH and RSS products), it only uses the satellite spatial pattern to fill the data holes. -stefan]

  26. 26
    Harry W. says:

    ” I was hoping for a comment on where this paper fits in the scientific consensus, and what kind of uncertainties are involved.”

    No, you weren’t: had you that intent, you would have said so, in your OP. Your motive was to play the man, and not the (published) ball, and to cast aspersions upon that ball by casting doubt on the men.

    Your intent was fully laid bare when you wrote this: “These are not the qualifications I would expect for the authors of such a ground breaking paper.”

    In your later post, you admit to not being qualified to comment upon the paper: what makes you qualified to arrive at the above statement (your exact words)?

  27. 27
    dan bloom says:

    see CLI FI CENTRAL blog on climate issues and SEA SPARROW taifoon name in English sigh RIP all 10,000 souls

  28. 28
    Steve says:

    I am a climate change blog newbie, a citizen barely informed on this topic, hoping to make sense of it. While I expect my readings will lead me to confirm my conviction that AGW is a real and present danger, I am suspending that conclusion to see if I can have it bolstered empirically by following what I see as quality blogs on both sides of the debate.

    My comment here is that Blair asked a reasonable question. For people who cannot decode the science in published papers, understanding qualifications is useful.

    My experience of these blogs is that people write unnecessarily mean-spirited things, such as those written criticizing Blair. When I read posts like that the credibility of the blog takes a ding. I see similar things on “skeptics” blogs. What I hope for on these blogs is carefully reasoned explanations of the science.

    Further, qualifications, as somebody above pointed out, do matter. For example, the Anderegg paper, trying to establish the 97% consensus, made much of qualifications. I agree that the science should stand on its own. In fact you’ll find that very argument made forcefully at the WUWT blog in discussion of the “consensus” papers. But for those of us who cannot decode the scientific arguments, and find them contradicting each other, qualifications are some guidance.

    Similarly, I suspect that people on this blog would find things to say about the qualifications of skeptic posts here or on other blogs. (Please don’t bring in the bit that all skeptics are wholly unqualified dentists, etc. While I agree that there are tons of citizens who are denying climate change based on faith, so far I am seeing plenty of skeptical blog posts that are trying to crunch the numbers, and have reasonable sounding objections).

    Blair’s post was maturely stated and asked a reasonable question. The criticisms, to me, lost credibility for being antagonistic.

    Please, folks, leave out the flaming, and stick to carefully explained scientific reasoning.


  29. 29
    Bruce Tabor says:

    Presumably this finding will not make it into the IPCC’s Fifth Assessment Report (AR5). That would go a long way to countering the damage the “warming pause” message has done in regard to action on climate change.

  30. 30

    To Blair, Before you mentioned it, I didn’t know that Kevin Cowtan was an expert at X-ray crystallography but it makes sense. I did diffraction theory for my PhD and I can tell you that this is puzzle solving at its finest — trying to piece together reality using limited data and wave interference prepares one for just about any challenge.
    Fine work.

  31. 31

    Warming at high latitudes: This was suspected based upon pretty sound arguments by Arrhenius in 1896, per S. Arrhenius, “On the influence of carbonic acid in the air upon the temperature of the ground”, Philosophical Magazine and Journal of Science, London, Edinburgh, Dublin, April 1896.

    Always good to see what appears to be a “gap” closed. Of course, to the degree that conservation of energy applies, this kind of thing HAD to be true, going somewhere.

  32. 32
    Doug Bostrom says:

    I am a climate change blog newbie, a citizen barely informed on this topic, hoping to make sense of it.


    For example, the Anderegg paper, trying to establish the 97% consensus, made much of qualifications.

    There’s a problem with that juxtaposition.

    Method acting is not easy; great actors make immersion in a character look effortless but doing so requires a special kind of mindfulness, means entering a sort of hypnotic state. A misplaced twitch of the lips due to remembrance of a happy moment while portraying a simulation of grief ruins the whole show.

    Similarly, if a person is acting the role of a naif on a given topic, blurting out a nugget of specialized arcana during the performance ruins the entire effect.

    Good job with swerving the topic to matters of delicate comportment, though.

  33. 33
    Steve says:


    This is the last I will post on this, because I don’t believe in flame wars, and the topic of the blog post is much more important. I am indeed a blog newbie. I started reading climate blogs three days ago. The first thing I was curious about was where does the media’s (and my own) off-cited 97% consensus come from. I found the answer on this page,, in the references. I read the Anderegg paper forthwith, to see if it was persuasive. Seemed reasonable to me. Next stop was the WUWT blog. That blog was pointed out by a friend as being a skeptic blog worth watching. I was curious what comments they had there about the paper I has just read. I found an analysis of it and other consensus papers. As I wrote to my friend, I thought that analysis was “full of sh-t” (part of its argument was that consensus is irrelevant in science, what matters is only the science itself).

    So you are off track with your not-nice comments about me, as well as yours about Blair.

    All this is besides the point. What I am interested in is comparing discussion of the Cowtan paper, which to my newbie eye seems important, on this blog and on WUWT, where I imagine a skeptic discussion will crop up.

    I will be assuming agnosticism, though expect to be persuaded by the mainstream, but am open-minded. Posts by antagonistic people don’t persuade me. In fact, anything they say subsequently is suspect.

  34. 34
    Doug Bostrom says:

    “Steve”: Further, qualifications, as somebody above pointed out, do matter.

    …stick to carefully explained scientific reasoning.

    It’s not possible to ignore the logically disastrous combination of those two specifications.

    Is it so very difficult to understand that from the perspective of discussion of the validity of a scientific paper, referral to author biography is entirely a pointless distraction? Sticking to “carefully explained scientific reasoning” means confining the topic to the subject of the paper, nothing else.

    As usual, everything is information. Here we have a number of parties attempting to insist that personal aspects of authors are somehow important to a scientific discussion. The “here and now” begs the question “why this, now?” Perhaps it’s because there’s no other approach to reassembling Humpty Dumpty?

  35. 35
    Dave123 says:


    You thought what I wrote attacked you personally?

    There are contexts and there are contexts. You may have wandered into one by mistake. But I’m skeptical.

    The difference between the retired dentist opining and Cowtan and Way getting a complicated paper published should be clear and compelling. C&W getting past peer review should be a signal that the competence of the authors has passed scrutiny in the first form that matters. We’ll see how the work holds up in the future.

    In the meantime, I wonder do you get why a retired dentist opining in the blogosphere and a couple of scientists getting their work published are greeted differently?

  36. 36
    Michael Sweet says:

    Robert Way has published 4 papers. All are on the subject of climate change. The suggestion that only one is relevant is false. He is a graduate student, how many papers do you expect? One of his papers is the widely discussed paper with the group from Skeptical Science (where he posts regularly) on scientific consensus. Two big hits and he is only a graduate student! What will he publish next year?

    Stephan states in the OP that “We knew about the study of Cowtan & Way for a long time”. Obviously that means that it was vetted before publication widely among skilled reviewers. This paper is not a blog post written up late last night. This fact might not be so clear to the non-scientists present.

    My understanding is that Robert is an Inuit native to the Arctic. To me that suggests he has deeper roots than those who have not been directly affected as much by climate change.

    Steve: who did you see post on WUWT that has as much scientific credibility as Robert Way? Most of the posters there have done no science at all. Anthony Watt does not even have a college degree. Why do you question real scientists and trust the “quality blogs on both sides of the debate” like WUWT?

  37. 37
    Tim Jones says:

    Ref: 28>11

    Steve’s comment isn’t flaming but it’s still a neophyte putting down people that know what they’re talking about without confining himself “to carefully explained scientific reasoning” at all.

    He writes: “My comment here is that Blair asked a reasonable question.” “Blair’s post was maturely stated and asked a reasonable question.”

    Blair Dowden didn’t ask a question. He cast an aspersion on the paper by impugning the authors of the paper’s qualifications. To wit:
    “These are not the qualifications I would expect for the authors of such a ground breaking paper.”

    This is Blair Dowden the apologist for Roy Spencer, right?

    It seems to me from checking Dr. Cowtan’s publications that he offers an expert’s statistical analysis offering insights into a problem that was posted by the Quarterly Journal of the Royal Meteorological Society – a body of qualified scientists.

    Do we have a problem with them, too? Not to mention Stefan Rahmstorf who saw the merits of the paper enough to post the message? Perhaps Cowtan is just at the top of the list of Dowden’s impugnations today.

    The fact that this paper helps dispel confusion about the onslaught of continuing climate change and should help dispel complacency about doing anything about it. It’s a valuable contribution if it proves out.

  38. 38
    Shelama says:

    Doug Bostrom quoting Blair: “For example, the Anderegg paper, trying to establish the 97% consensus, made much of qualifications.”

    I’m thinking that even for a naif climate blog newbie, and for a number of reasons, that a paper like Anderegg (2010) could well stick out in the mind.

    I’m with Steve @ 28: “But for those of us who cannot decode the scientific arguments, and find them contradicting each other, qualifications are some guidance…Blair’s post was maturely stated and asked a reasonable question. The criticisms, to me, lost credibility for being antagonistic…Please, folks, leave out the flaming, and stick to carefully explained scientific reasoning.”

    Gavin’s pointed but non-antagonistic response to frank maccioli @ 21, for instance, is appreciated by this relative naif and newbie.

  39. 39
    flxible says:


    …. quality blogs on both sides of the debate ….

    When I read posts like that the credibility of the blog takes a ding.

    Steve, aside from the fact that Climatology is not a “debate”, so there are not 2 sides, the comment section posts here are NOT “the blog”, that consists of the lead articles by the group of scientists known as “Real Climate”, for which see the Contributors link, the comments are from folks like you and me, generally non-scientists with varied opinions and sometimes clashing personalities.

  40. 40
    Svet says:

    RE: James Cross – “What’s more the satellite data shows the same pause yet now it is being used to show there is no pause.”

    This does seem strange. If you trust the satellite data enough to fill in the gaps in the surface data then why just go with the satellite data by itself since it doesn’t have the gaps?

  41. 41
    Chick Keller says:

    There are still some problems.
    First the oft used rationale that short periods without substantial rise have been seen before ignores the fact that GHG forcing now is much higher than in those past records and one might expect this higher forcing to make a difference.
    Second, it seems hard for such a small land area as the high Arctic to make such a difference in the record.
    Third, even the corrected data look to the eye as not much warming.
    Fourth, past warming had the same gap problem as the recent record and yet showed a marked increase. One might ask why this has not been the case and when we might expect it to reoccur.
    Fifth, we need to understand much better negative forcings since they seem to be able to stop GHG warming.
    This is a good piece of work and needed to be done, but I think I’ll wait to see if there isn’t something else here.

  42. 42
    MikeH says:

    Robert Way’s qualifications include Geomatics and Spatial Analysis. I would have thought that they would be a perfect background for this sort of study.

  43. 43
    Tony Weddle says:

    Dave, at comment 17, you beat me to the question.

    Stefan, are you working on updating your 2011 paper, which removes some of the natural variations affecting surface temperatures? Or perhaps have a feeling for the impacts of this work on that paper?

    A question on this paper: I’ve read that temperature anomalies are historically less in tropical zones, just as polar anomalies are larger. It was mentioned that there are gaps in Africa. Does the paper address those gaps as well as the polar gaps?

  44. 44
    MikeH says:

    And from Blair Dowden’s link for Way. GIS = Geomatics more or less.

    Research Interests:Geography, Geographic Information Systems, Remote Sensing, Remote sensing and GIS, Mountain permafrost, Permafrost, Glaciology, Glacial Geomorphology, and Remote Sensing in the cryosphere and climate change

    I am in a family of geospatial analysts. Kriging is a technique used in spatial analysis. Robert Way has the qualifications I would look for in a study of this sort.

  45. 45

    I wonder what the deniers who make a big thing of satellite data being best will make of this. No doubt satellite data is only better if it blosters their case. As are errors. When the AMSU-A data started going bad in 2008, nothing happened until 2010, when it made 2010 look as if it was an off-the-charts warm year.

    Whenever an unusual result appears, we need to allow a bit of time for rebuttals and corrections. This one at least is consistent with other data, like the rapid decline of Arctic sea ice, way ahead of any model predictions I’ve seen published prior to the decline.

  46. 46
    mike says:

    *I looked up Robert Way only because he lives in my city and I did not know any climate change work was done here. I was surprised he was only a graduate student (his site did not mention he is a PhD student* – Blair, #20

    And Albert Einstein was only a patents office examiner. And Charles Darwin was only a theology student.

  47. 47
    Jerry W says:

    I hesitated before posting this; there are some quite unpleasant comments above. But it is an important subject..

    I am not a climate change expert. Therefore I must perforce trust those who say they are, and listen carefully to their claims. So yes, the qualifications and experience of those who make specific claims of this kind do become important; and it would be naive to think otherwise. I accept there is something approaching a scientific consensus that global warming is real and should be addressed urgently, but contributions wishing to radically change the figures do need to consider credibility issues of this kind.

    If the claims this paper makes are true, I think they should be disseminated with some care because to the unqualified observer, they will tend to undermine the credibility of the whole body of research. “If they are right,” people will say, “Everything we have been told so far must have been quite wrong.” Greatly wrong, as the study itself says.

    I would be interested to know what form of peer review the paper has undergone?

  48. 48
    Chris Vernon says:

    Great paper, a really important result. However, for Figure 1 they state “Note that the cylindrical projection exaggerates the missing area at high latitudes”.

    Why not use an equal area projection! Area is critical to displaying these data. These days re-projecting data is a simple task, if you’re trying to communicate an area dependent variable please use an equal area projection.

  49. 49
    stefan says:

    A lot of what you have been told by the media might have been wrong, but if you had followed RealClimate over the years there’d be nothing very surprising in this for you. We have repeatedly reported about the Arctic data hole issue since 2008, and we have often made the more general point that short-term trends are not very robust and informative.That is also what IPCC said about this issue – quoted above. There is a lesson here about media hyping a pseudo-issue but not about climate science suddenly needing to be rewritten. -stefan

  50. 50
    CM says:

    Stunning stuff, if it holds up. Kudos to the authors, and to Rasmus Benestad as well; I read the 2008 post back when it appeared, but wasn’t aware that he was the first to raise the issue.

    The implications for public discussions of global warming are obvious. Would it be right to say, though, that this finding is not likely to make much difference for model-observation comparisons over the recent short-term period, because in such comparisons the models are masked by the observational coverage anyway?

    – –

    On etiquette, I don’t really take issue with Blair D. for raising the authors’ background; I plead guilty to doing the same as a lazy layman’s heuristic when I try to work out how much weight to place on a reported new result that seems to overturn a widely held view.

    But lazy heuristics will only take you so far, and Blair’s reaction to Dr Cowtan’s specialization reminds me of a supposedly true story of an awkward day at a U.S. institution when a visiting British scientist was confronted with her apparent abuse of her guest PC to surf for X-rated sites. As it turned out, the nanny software, pattern-matching on the first four characters only, had caught her red-handed looking at “X-ray crystallography”…