Has there been a “pause”?

Reiner Grundmann, who is a Professor of Science and Technology Studies at the University of Nottingham, yesterday tweeted the following statement and question.

I do find the question, in some sense, a little odd. It’s a bit like asking someone a very complex question and then insisting on a yes or no answer. Although I’m not an actual climate scientist, I responded to Reiner with some of my thoughts on the topic. I will say that I found the exchange quite intriguing (which shouldn’t necessarily be perceived as positive). I partly think I expected better from an academic. Of course, I have had exchanges with Richard Tol and Paul Matthews (what is it with the University of Nottingham, by the way), so should probably have realised that such an expectation was naive. I just didn’t expect Reiner to follow the “let’s misrepresent what the other person is saying” style of dialogue. Also being accused of being a “true believer” by a Professor of Science and Technology Studies – when pointing out that anthropogenic global warming is about energy, not just about surface temperatures – was a bit of a surprise.

Anyway, although Reiner may not actually be interested in my thoughts (or in an actual answer for that matter), I thought I might express my views here on whether or not there has actually been a “pause” and the significance of this apparent “pause”. Bear in mind, though, that I’m not actually a climate scientist and you might learn more from the comments than from the post itself.

  1. To answer the basic question of whether or not there has been a “pause” in the rise of global surface temperatures, the answer is probably not. Even if you start your trend calculation in 1998 (a very hot year) the Skeptical Science Trend Calculator will tell you that – with the exception of the RSS dataset – the likely trend is around 0.05oC per decade. Even the IPCC SPM says

    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).

    The numbers in square brackets are the 90% confidence interval and so there is a chance that the actual trend could be negative. Given this confidence interval, however, there is only a 20% chance of a cooling trend. I suspect that it is actually less likely than this (Victor Venema could probably clarify this though) as the scatter in the data is primarily real natural variations, rather than measurement errors, and so we can probably have more confidence in the mean trend than the basic statistics would indicate (although, I will accept that this isn’t a particularly statistically robust argument).

    Some do interpret the uncertainties being larger than the trend as implying that there’s been no warming (i.e., that the warming is statistically insignificant). That view is incorrect. This view would only be correct if you could show that no warming was the expected result. The uncertainties actually tell us something about the likelihood of different possible trends and tell us that the most likely trend is the mean trend of 0.05oC per decade. Furthermore, such large uncertainties are perfectly normal for such short time intervals so should not, in themselves, be seen as anything particularly significant.

    So, the surface temperature datasets (with the exception of the RSS dataset) are themselves not consistent with a “pause” in surface temperature rises since 1998. A slowdown, maybe, but not a pause. One should also bear in mind that 1998 was a very hot year and, so, the subsequent trend is likely to be lower than if a slightly earlier year was chosen (the trend since 1995 is close to 0.1oC per decade). One can also consider the land only datasets, which show much more warming than the global datasets, although do have larger uncertainties.

  2. Another point is that the “pause” only refers to surface temperature. The ocean heat content continues to rise and Arctic sea ice extent (and volume) continues to decline. The rate at which the total energy in the climate system is rising (1022J per year) is also consistent with what would be expected and so implies that the fundamentals of anthropogenic global warming (AGW) are robust. The so-called “pause” doesn’t, in any way, suggest that there are problems with the theory of global warming.

    Some seem to think that AGW theory implies that atmospheric greenhouse gases simply act to increase surface temperatures. This isn’t fundamentally correct. Atmospheric greenhouse gases act to trap outgoing longwave radiation, causing the total energy in the climate system to rise. Some of this energy goes into the oceans, some melts polar ice, and some heats the land and atmosphere. So, yes AGW theory does predict that global surface temperatures have to rise (and, in fact, they need to rise so as to reduce the energy imbalance) but that is not the be-all and end-all of AGW theory. Fundamentally it’s about increasing the energy in the climate system, some of which acts to increase surface temperatures.

    Something Reiner implied was that switching from surface temperatures to energy was an attempt to mislead (or implied that the IPCC had been misleading people if I implied that they had done so). No, talking about energy – rather than surface temperatures – is simply because energy is the fundamental quantity. That’s why there are a number of figures in the IPCC documents that show how radiative forcings (measured in energy per square metre per second) have changed since 1750. This illustrates by how much the energy in the climate system must have increased since that time. However, these figures typically only indicate anthropogenic forcings and so do not include other, indirect, forcings and feedback that will likely increase the net change in total energy.

  3. There’s also the issue of variability. I don’t believe any climate scientist has ever indicated that surface temperatures should rise smoothly and monotonically. It’s clear that there is an element of internal/natural variability. Tamino has a recent post showing that although the previous 15 years have seen slower surface warming than expected, you can easily find a different, recent, 15 year period when the surface warming was much faster than expected.

    Also, only a small fraction of the excess energy associated with AGW heats the surface. Therefore small changes in the energy entering other portions of the climate system can have a big effect on surface warming. There have been a number of recent papers trying to understand the so-called “pause” (Kosaka & Xie 2013 for example) and none, as far as I’m aware, suggests that the recent slowdown is anything other than simply a consequence of some kind of internal/natural variability (ocean cycles, aerosols).

  4. Another issue is whether or not the “pause” could continue for a significant period (20 more years for example). Currently, we have a top-of-the-atmosphere energy imbalance of about 0.5 Wm-2. If the so-called “pause” were to continue for another 20 years, the surface temperatures (assuming the trend is 0.05oC per year) would rise by 0.1oC. This means the surface flux would increase by 0.5 Wm-2. Atmospheric CO2 concentrations would also, however, rise by 40ppm which means that the adjusted radiative forcing would also increase by 0.5 Wm2. This, however, ignores other indirect forcings and feedbacks and so the actual rise will likely be higher. This means that the total energy in the climate system will be accruing faster than it is today (and this will be even greater if people assume “pause” means no rise in global surface temperatures). If the “pause” is to continue, then that would suggest an ever increasing fraction of the excess energy will have to be entering the oceans.

    So, the only way the “pause” could exist for an extended period is if an ever increasing fraction of the energy excess “hides” in the oceans and also if we managed to avoid another 1998-like El Niño event – which may be surprising given the amount of energy accruing in the oceans.

So, there you go. My thoughts on whether or not there’s been a “pause” and the significance of the so-called “pause”. Basically, there’s been no “pause” in overall warming and no actual “pause” in surface warming. Should climate scientists clarify this in some simple way? I think some have been trying to do so (by actually pointing out that there hasn’t been a pause), but it isn’t some simple yes there has, no there hasn’t type of situation. Surface temperatures clearly are rising (since 1998) slower than expected, but this is most likely because 1998 was a particularly hot year and because internal variability can influence surface warming even if it doesn’t, significantly, influence overall warming.

There’s also certainly some indication that the whole discussion of the “pause” did not originate from climate scientists themselves, but from those who are openly “skeptical” of climate science. The reason it hasn’t been addressed, by climate scientists and the IPCC, in a manner satisfactory to some is simply because it is not appropriate (scientifically at least) to do so. It’s a pity that a Professor of Science and Technology Studies doesn’t at least recognise this as a possibility.

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61 Responses to Has there been a “pause”?

  1. I prefer to speak of “plateau” than “pause”, for obvious connotative reasons.

  2. “Plateau” may be a more illustrative but even that may not be strictly correct – “gradual plateau” maybe 🙂

  3. Reich.Eschhaus says:

    I prefer a cycling term: False flat

    [search Google for “what is a false flat”]

  4. Rachel says:

    False flat: perfect!

  5. BBD says:

    Call it what it is: a slowdown in the rate of surface/tropospheric warming. False flat needs looking up, so for me is too complex and confusing. Sorry.

  6. BBD says:

    RG sounds like he is pushing the standard conspiracy nonsense: the IPCC is lying to the world about the scientific evidence for AGW. Objectively, this is quite mad.

  7. I can’t claim to understand what RG was pushing, but I did find it a rather strange discussion.

  8. Did I hear my name? Yes, I am exploring the possibility that the land surface temperature is bias and the most likely direction would be that the true trend is larger. I would expect most of that bias to be in early measurements (radiation errors), thus I am not sure whether this could be used to explain the pause. It is not impossible, though, modern *ventilated* automatic weather stations may have less problems with strong insolation as previous stations. To be clear, there is no evidence for that at the moment.

    The reason the pause hasn’t been addressed much by climate scientists is likely that no one expected to be able to say much about such a minor deviation of only one or two tenth of a degree. I am impressed by recent studies that seem to have been able to do so, such as the ones mentioned above. It if very weird, that people who do not accept the science that there was a temperature increase of 0.8°C over a century, make a fuss about such a minor slow down.

    Maybe one should add that Reiner Grundmann is Professor of Science & Technology Studies at the Faculty of Social Sciences. He thinks about science, he does not do science.

    (And you typed his name wrong in the first sentence.)

  9. Steve Bloom says:

    In which we learn that anyone who makes the sweeping claim that climate science is not falsifiable is probably some variety of denier.

  10. One does not simply enjoy false flats in Mordor.

  11. > what is it with the University of Nottingham, by the way

    Good question.

  12. dbostrom says:

    Grundmann was only donning a costume and striking a pose, adding to our tableau vivant, not asking a question. Answering only spoils the effect.

  13. > what is it with the University of Nottingham, by the way

    Group thinking perhaps? The very thing they accuse others of doing. Funny to watch.

    After all, Grundmann is a social scientist. What could we possibly learn from an atmospheric science point of view? Apart from that … well … I better keep my mouth shut …

    Btw, pause is (per definition) when the long-term trend has reveres. It hasn’t! In the unlikely event that it does reverse one day … there is physics to explain it 😉

  14. There I go again, mis-understanding what people are really trying to say 🙂

  15. Marco says:

    You called? Ah no, you didn’t, and last time I was pretty good at keeping myself back, but not today.
    Reiner Grundmann is the author of a hopelessly flawed paper, which was silently modified. In that paper, with the ironic title “Climategate and the scientific ethos” (with “ethos” the ironic part), Reiner Grundmann repeats an incorrect story about discussions between some IPCC authors at a meeting about the three paleoclimate reconstructions shown in the TAR. The story originated with Steve McIntyre in 2009, who within days had to correct his narrative, because Deepclimate showed that McIntyre had snipped the parts of the e-mail that completely and utterly contradicted the narrative. Note: McIntyre corrected his story, but not without claiming there were other supposed problematic issues. See for some of the gory details http://deepclimate.org/2009/12/11/mcintyre-provides-fodder-for-skeptics/

    By that time, Roger Pielke Jr had already taken over the story, but as far as I know he did not correct it. Grundmann, several years later, then took Pielke’s quotes as his source (yes, we are now looking at a tertiary source). A commenter on Klimazwiebel pointed out the correction, but Grundmann didn’t want to hear any of that. And thus it remained, even in the ‘corrected’ version.

    Now, this is bad enough, but in the same article Grundmann also reads several different motives in an e-mail by Phil Jones that even in its snipped form requires a lot of wishful thinking. We all remember the “even if we have to redefine what peer-review literature is!”, with Jones referring to what he considered to be “crap” papers that were wrong which he did not want to cite in the IPCC report. In Grundmann’s alternative universe, this became, among further misrepresentations of what was said in that e-mail, evidence that Jones wanted to keep papers by competitors from being published.

    Regarding the ‘silent correction’: the original paper I downloaded (as accepted paper), quite soon after it was promoted on Klimazwiebel, has some differences with the final version, but that final version does not show anywhere that significant changes had occurred compared to the original accepted version. One added footnote is funny, because it appears to admit that the referencing is deliberately biased towards “critical accounts”.

    And to end this diatribe: Grundmann also referred in that paper to Jones’ unwillingness to share data with ‘skeptics’, but could have kept that much closer to home. His dear friend Hans von Storch declined to share data with people at PIK regarding their criticism of MBH98 (which to be fair was also somewhat critical of M&M’s criticism) because according to von Storch the request was just “political”:
    “Zurück kamen damals aber zunächst keine Daten, sondern die Unterstellung, wir fragten nur aus politischen Motiven an.”

  16. Thanks, Victor. I think I’ve written his name wrong before, which is not intentional. I was trying not to play the “social scientist” card, but it is tempting 🙂 In fact, I was tempted to write someone about STS and the role that it appears to be playing, but I then realised that my views of STS are based largely on a single institution (Nottingham) and so realised that I should be careful about generalising based on a single data point.

  17. Personally, I use statistics: I have a cut’n’paste for it.

    30 years is the accepted norm for climate discussion. If you must use too short terms you will note that the “pause” is not statistically significant. For any of the instrumental series, over any time span ending in the present:

    • There is no period where warming is invalidated, against a null hypothesis of no warming. None.
    • Against a null hypothesis of the long term warming trend, there is no period where a “no warming” hypothesis is validated. None.
    • Over any period with enough data to show statistical significance, that data shows a statistically significant warming trend. Always.

    No one seemed concerned over the 15-year time span covers the years 1992 through 2006, during which the rate of warming was 0.28 deg.C/decade. That’s a lot faster than the warming rate from 1975 to now. The time-scales were too short for alarm then. They’re too short for complacency now.

  18. Yes, I was going to discuss how one might use the null hypothesis but the post was getting a bit long. You’ve pretty much done it here, though. Thanks.

  19. It is quite remarkable how so much ends up relying on (or ending up being based on) a bunch of emails, most of which appear to have been mis-interpreted.

  20. verytallguy says:

    I thought I’d look at what AR5 has to say on the subject.

    There’s a graphical summary, fig 10.20, and the following two quotes are taken from ch 10 and ch 12:

    The observed recent warming hiatus, defined as the reduction in GMST trend during 1998–2012 as compared to the trend during 1951–2012, is attributable in roughly equal measure to a cooling contribution from internal variability and a reduced trend in external forcing

    (my emphasis)

    The lower limit of the likely range of 1.5°C is less than the lower limit of 2°C in AR4. This change reflects the evidence from new studies of observed temperature change, using the extended records in atmosphere and ocean. These studies suggest a best fit to the observed surface and ocean warming for ECS values in the lower part of the likely range. Note that these studies are not purely observational, because they require an estimate of the response to radiative forcing from models. In addition, the uncertainty in ocean heat uptake remains substantial. Accounting for short-term variability in simple models remains challenging, and it is important not to give undue weight to any short time period which might be strongly affected by variability

    So the IPCC define it as a reduction in trend of warming rather than an pause in warming, and term it a “hiatus”

    Perhaps rather than debate if there is a “pause”, a better way to view the recent surface record is what it adds to our understanding, one measure of which is what constraints it puts on sensitivity.

    My (very weak) understanding is then that the surface record between 2006 and 2012 (AR4 to AR5), or our understanding of climate, or both, resulted in the lower bound of 2 degrees/doubling being reduced to 1.5.

    Thus we should acknowledge that the “hiatus” is real, and does change our understanding of future climate, albeit not very significantly.

  21. I do agree with what you say. So, what I was saying in the post is it is clear that there’s been a slowdown but, technically, one can not call this a “pause” since it hasn’t actually paused. The IPCC comment

    attributable in roughly equal measure to a cooling contribution from internal variability and a reduced trend in external forcing

    is interesting because the reduced trend in external forcing would be significant if it is long-lived but – as far as I understand it – this may simply be aerosols which (if I remember correctly) could reduce as we clean up our emissions. So it’s real but, possibly, in terms of long-timescales, doesn’t necessarily imply that our expectations should be different – which, I think, is what the later paragraph you include is indicating.

  22. verytallguy says:

    From my reading actually probably volcanoes and the sun, but might be human emissions of aerosols. Here’s the rest of the paragraph:

    The forcing trend reduction is primarily due to a negative forcing trend from both volcanic eruptions and the downward phase of the solar cycle. However, there is low confidence in quantifying the role of forcing trend in causing the hiatus, because of uncertainty in the magnitude of the volcanic forcing trends and low confidence in the aerosol forcing trend. Many factors, in addition to greenhouse gases, including changes in tropospheric and stratospheric aerosols, stratospheric water vapour, and solar output, as well as internal modes of variability, contribute to the year to year and decade to decade

    I think it does imply a slightly different expectation – a higher likelihood of lower sensitivity.

  23. verytallguy says:

    So, how should this be honestly communicated? I personally don’t think it’s completely transparent to switch to OHC as a primary measure of warming, as some can appear to want to, informative as it is. So here’s my stab:

    1) There is a slowdown in warming over the past 15 years or so, termed a “hiatus” in the latest IPCC report.

    2) Variability of the surface temperature on this timescale is not unexpected; much longer time periods are necessary to smooth out natural variation.

    3) Observing and understanding this slowdown has slightly reduced our future projections of temperature increases.

    4) Other current measures, such as ocean temperatures, strongly suggest greenhouse gases are continuing to add heat to the climate much as expected.

    5) Current temperature measurements are only one small part of our overall understanding of the climate and it’s likely changes into the future. Other data such as analysis of past ice ages, suggests much higher future warming.

    6) All credible future estimates of global temperature still project human induced warming causing a radical change in the earth’s climate in a geologically short time period.

    But of course, this misses the point. The reason the “pause” is mentioned so much is to spread a message of doubt and uncertainty, and continue to prevent political action. It’s not motivated by a desire to understand the climate.

    The rhetoric is extremely effective. My dentist mentioned in passing to me yesterday that it had stopped warming and scientists had a vested interest in hiding the fact… a view from a well educated and scientifically literate layperson.

  24. Yes, you may be right. Certainly true that solar forcing has reduced (slightly). I wasn’t quite sure what was driving the aerosols. Looking at figure 8.19, it seems that natural forcings have been -0.1 Wm-2 since 1998. Looking at figure 8.20, the anthropogenic aerosol-cloud since 1980 has been about -0.25 Wm-2 so – not quite the same time interval – but it does seem that it might be a combination in reductions in natural forcings and some anthropogenic component due to aerosol-cloud interactions.

  25. Yes, I’d agree that what you say is perfectly reasonable way in which to communicate what has happened since 1998 and the significance of the so-called “hiatus”.

    Of course, I think your last paragraphs are correct. The push to get scientists to explain the “pause” is not, in my opinion, to improve our understanding but an attempt to get scientists to acknowledge something that appears to disprove AGW. So, it’s a tactic rather than an honest attempt to understand the climate.

  26. verytallguy says:

    Fig 8.19 does seem to show -ve natural forcings but doesn’t slit out anthopogenic aerosols, which as I understand are highly uncertain anyway. Fig 10.6 doesn’t show much obvious volcantic trend and seems to contradict the text above.

    But I’m now well beyond any expertise I have and into speculation, I’m sure others can add more light to this than me.

  27. I have no problem mentioning that he is a social scientist, maybe because I am one of the few natural scientists that respects the social sciences. Still with respect to a climatological questions, such as the pause, he is no expert. Just like I am no expert when it comes to the reception of climate change in the media. (If I only knew about climate change from the press, I might be a climate ostrich as well.)

  28. BBD says:

    Yes. The slowdown in the rate of surface/tropospheric warming may turn out to be one of the worst things that could possibly have happened. It has been pure gold for the deniers and their industrial sponsors and political enablers.

  29. idunno says:

    Climategate relates to Watergate only insofar as Watergate revealed the shocking attempts of McGovern to get elected POTUS.

  30. dana1981 says:

    Grundmann sounds like he’s got some serious anti-science issues for a social science faculty member.

    The answer is yes, there is a pause, if you cherry pick the data. Start at 2002 and you can find a flat or slightly negative trend. But that’s double cherry picking, because it requires a careful selection of start dates (cherry pick #1) and requires focusing only on the 2% of global warming that occurs in the atmosphere (cherry pick #2). His claim that it can’t be both a real thing and a cherry pick is totally wrong. It’s real *if* you cherry pick the data.

    My next post was going to be about the ‘pause’ or ‘hiatus’ or ‘speedbump’ or whatever you like to call it (the latter is probably most apt). Maybe I’ll incorporate Grundmann’s question into the post.

  31. Yes, that’s a good point. I had considered mentioning that you could find negative trends if you choose a sufficiently short period, but the uncertainties are so large that I assumed noone would seriously consider that as evidence for a “pause”. In retrospect, that was probably a rather naive assumption 🙂

  32. KR says:

    There’s an excellent Java tool for exploring time frames and trends on Hot-Topic here – it allows you to pick a length of time and see _all_ trends of that length over the GISS or HadCRUT3 data. If you pick a sufficiently short time period you get lots of trend variations both positive and negative. But if you look at 25-30 year time periods, actual climate rather than weather, not so much…

  33. That's MR Ball to you. says:

    Nevertheless, one would expect that the study of climate change as a social issue would be a priority for anyone engaged in “Science & Technology Studies”. Has there every been a more interesting and important aspect of science as it relates to a range of social interests, that we can study in real time?

  34. I agree and that is what I assumed STS was essentially doing with regards to CC/GW. However, it seems that there are some (and maybe centred round the University of Nottingham) who are not obviously behaving as dis-interested observers. So, there is a concern that I have that some of what is happening in STS is giving an element of legitimacy to sides of the debate that have very little – if any – actual scientific credibility.

  35. toby52 says:

    I agree.

    The surface rate has slowed down … a slowdown is easily understandable to a lay person.

    The term “pause” has semantic difficulties .. a pause does imply it must end sometime, or does it? Deniers seem to expect a neverending pause.

  36. toby52 says:

    Needs a good Sheriff?

  37. I thought the sheriff was the problem.

  38. BBD says:

    That was then…


  39. I hope you changed dentists. He has a vested interest in over-elaborate dental work.

  40. johnmagenta says:

    I must admit my prejudice- the moment I saw that he was working in the field of Science and Technology STUDIES, my bulld*st detector went into overload. In my experience, any field that adds ‘Studies’ after its name has to work very hard to convince me that it is earning its keep and generating useful outputs.

    RG has unfortunately reinforced my prejudice. If he’d been commenting on why the issue of global warming so polarises the community, or why AGW denialism seems to be mainly an English-speaking phenomenon, or why the community doesn’t want to hear what the science is saying, I would have read his view with interest.

    But as a non-scientist, he’s questioning the science, and in the process making himself look either disingenuous (if he knows the answer but still asks the question) or thick (if he doesn’t know the answer, and won’t/can’t research the issue himself. Would it be too much to ask him to go away and read the relevant bits of AR5?

  41. To a certain extent you highlight some concerns I have with regards to STS. I’m still don’t quite understand how they’re motivating, sometimes, their research and what they see their role as being. Is it objective observers or active participants (which, given that most are not actually physical scientists, seems a little unjustified).

  42. Marco says:

    Right now, live, on Klimazwiebel:
    “Hmmm, I don’t think Oreskes said that the ‘pause’ was the ‘result’ of cherry picking data, but rather that making certain claims about a so-called pause is based on cherry picking data, if I understand her correctly. I think she wanted to stress that one should not make claims about data that are taken out of context….

    As a response to:
    “On October 7 Oreskes gave a talk in which she declares that the so-called ‘pause’ or ‘hiatus’ in global warming is a result of cherry picking, see here (at 26′)
    The IPCC which published its WG1 report shortly before, has acknowledged the problem of the ‘pause’.
    [h/t Brigitte Nerlich]”

    The most interesting thing will be to see if Grundmann retracts his claim. I predict he will not. Anyone dare to put 10 pounds against me on that? 😉

    The rest of that comment thread, in particular the comments of “hvw” responding to Grundmann are also of interest.

  43. I was briefly involved in the exchange where Brigitte pointed out what Naomi Oreske had said. Reiner’s tweet after seeing that portion of the video was

    Which then continued as

    He didn’t really answer my question as to what data the IPCC were ignoring. Apparently it all relates to Oreske going off message. It seems that some think that if you generally accept the IPCC reports then you’re not allowed to say anything that might be perceived as even remotely contradicting what is in the IPCC reports.

  44. BBD says:

    RG is all attitude and no substance and as such should be ignored. He is posturing, exactly as dbostrom said above.

    I have no patience left for these types of “commentator”. They are ignorant, they are biased and they are wrong. They should acknowledge their errors and fall silent – with public apologies – as they have done enough damage already.

    But no. Yack, yack, yack. Twitter, twitter, twitter. Idiots.

  45. Brigitte says:

    I should say that I am neither a climate scientist nor Oreskes, so how I interpret what she says might be completely wrong….

  46. Brigitte, thanks for the comment. I’m not a climate scientist either but, from what I saw of the video, how you’ve interpreted what Naomi Oreske says seems about right. I just found it odd that Reiner would appear to be criticising the concept that one should consider all the information and not just some of it. Also, quite what Reiner meant with “need to apply it to IPCC as well, not only ‘deniers'” is slightly beyond me. What is the IPCC ignoring?

  47. BBD says:

    Note the conspiracist ideation by RG: the strong insinuation that the IPCC is deliberately misrepresenting the scientific evidence. As I said upthread, this is not credible and effectively exiles the user from reasoned debate.

  48. johnmagenta says:

    Perhaps someone needs to suggest strongly to RG that he should write something longer than a tweet, in which he sets out in detail what his concerns are. I suspect he would be somewhat reluctant to do this because it would demonstrate to one and all the depth of his understanding of climate science. Much safer to maintain an air of assumed authority by tweeting hints of conspiracy from the sidelines.

  49. C.V. Danes says:

    If you are driving your car and, while keeping the accelerator at a constant position, it slows down while climbing a hill, does that mean your engine is producing less power? Is it possible to increase the power output of the engine and still be slowing down, assuming a large enough hill? And would not the car, thus, accelerate faster than normal once the road leveled out?

    I suspect that the energy imbalance causing global warming is similar.

  50. Back in 2007 when I first started commenting on the pause, I was astonished by the way a statement of fact: “it has not warmed in the last … 6** years ” was so controversial.

    When I first mentioned it, I assumed the conversation would quickly revolve around the scale of natural variation and whether 6 years was significant and what it meant. What I hadn’t considered was outright denial (plus having to explain what linear regression was to many people who denied it).

    Little could I have imagined then that 6 years later, that I would still find anyone denying the pause. It may be dressed up more but it is just simple refusal to admit that a trend exists which was not predicted.

    It is like denying a pothole or denying a speed bump. You can argue about whether it is a significant pot-hole or whether the speed bump would cause a driver to slow down, but you can’t say it doesn’t exist. You could even argue that given the general quality of the road – that any one hole it is not significant to be readily identified as “one” pothole – but whatever argument you use to deny the pause, the mere fact you are using the term “pause” is enough to mean it exists.

    **I started from 2001 to avoid problems of the starting point.

  51. I’m slightly confused by what you seem to be suggesting. Indeed, if you start in 2001, the mean trend is very small. If you ask the question “is the mean trend in surface temperatures since 2001 close to zero?”, the answer is indeed yes. So, if you’re accusing me of denying this, then you’re incorrect. I do no such thing. In the post, I was really talking about the period 1998 to now. As you acknowledge, however, such a short time interval has large uncertainties. Considering such a short time interval also means variability is much more prominent. If you consider other time intervals of the same duration, the variability is quite remarkable. So, if you want to know if agree that the mean trend since 2001 has been close zero, then I do. Do I think it has any significance, no I don’t.

    Plus, you can’t say “I started from 2001 to avoid problems of the starting point” because that is really as much of a cherry-pick as starting in 1998. All you’ve done is make the period short enough that variability will almost certainly play a big role in determining the trend. Choose 1991 – 2003 and the trend is around 0.28 degrees per decade. In 2003, noone was claiming that this meant that rapid warming would continue. The same applies now.

  52. BBD says:

    Banging on endlessly about a slowdown in the rate of tropospheric warming while ignoring the continuing increase in OHC is dangerously partial. It is to obscure the fact that the troposphere is only a small part of the climate system, which is mainly ocean. It is to risk confusing and even misleading people. It is to avoid emphasising the words “natural variability” and “transient”.

    So why do it? Why go on and on about this as if it had a bearing on the robustness of the scientific understanding of AGW?

    That’s not even remotely sceptical.

  53. OPatrick says:

    Scottish Sceptic, I wonder if you are misremembering these conversations? My memories of similar conversations I’ve had tend to involve someone claiming there has been a pause in warming (without qualifying this by recognising that the temeprature record is only for one component of the global system and without acknowledging the noisy nature of the data and the lack of statistically significant deviation from the ongoing warming trend) and drawing exaggerated and largely unjustifiable conclusions from this. Often when the qualifications were pointed out and the exaggerated conclusions challenged subsequent comments implied, or at times directly stated, that I was denying the pause.

    This is a common tactic from ‘sceptics’ in my experience. Take a point of marginal scientific significance and make unjustifiable claims on the basis of it. When these exaggerations are challenged claim that we are being defensive, even whilst the core claim has been acknowledged (and in most cases widely discussed already).

    I wonder if your “a trend exists which was not predicted” fits this pattern? It’s not clear that the current trend, even only in surface atmospheric temperatures, is outside the range of projected temperatures. It’s certainly a simplification to talk of a trend which was not predicted.

  54. Vinny Burgoo says:

    My memory tallies with Scottish Sceptic’s, but my memory is shite so I turned to Wikipedia.

    Until August this year, if you asked Wikipedia about _Ocean heat content_ it directed you to an article about _Sea surface temperature_. A few months later and _Ocean heat content_ has an authoritative-looking article of its own. (Authoritative-looking? Impressive algebra, writ large. Scientist peering thoughtfully at his fingers. An animated globe.)

    Wikipedia’s climate coverage used to be about fighting the climate wars as much it was about communicating climate science. That OHC has only just been granted its own article suggests that this is still so – and it supports the notion that surface temperatures were everything until quite recently.

    Or not. I’m not wholly serious. A data point presented with the last drips from the bottle.

  55. BBD says:

    So because Wikipedia has added an article (which is, hey, what it does, all the time), it is engaged in propaganda? “Fighting the climate wars”?

    A data point presented with the last drips from the bottle.

    I’m not sure I’m reading you correctly here, but this seems to imply that there is an element of desperation involved in pointing out that ocean heat content continues to increase and that the climate system is predominantly composed of ocean.

    Yet these facts are no more controversial than Wikipedia adding a new entry. Nor are they new.

    Informative and objective discussion of climate change includes these things and does not hyperfocus on tropospheric/surface temperature alone. Certainly this has been omitted from far too much science communication in the past, but that doesn’t imply (perhaps insinuate expresses it better) that there is any fundamental problem with the scientific understanding of AGW.

    So we should be careful what we say, yes?

  56. Vinny Burgoo says:

    ‘Certainly this has been omitted from far too much science communication in the past…’


    ‘…but that doesn’t imply (perhaps insinuate expresses it better) that there is any fundamental problem with the scientific understanding of AGW.’

    No, it doesn’t.

    (‘Last drips from the bottle’ meant only that I had just run out of booze. Sozzled solipsism, if you like.)

  57. BBD says:

    No problem with sozzled solipsism (which I cannot spell, drunk or sober). The human condition, innit?


  58. OPatrick says:

    ‘Certainly this has been omitted from far too much science communication in the past…’

    Ah, a classic manoeuvre – something which has long been acknowledged and discussed is presented as though it is a first step in your direction. If only now we could take those next few steps towards your own reasonable middleground?

  59. BBD says:

    Shifting the Overton Window.

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