IPCC 5th Assessment Review

I’ve finally had a chance to listen to some of the evidence presented to the Select Committee on Climate Change and Energy. It’s long and I haven’t listened to it all, so I thought I would jot down a few thoughts. I’ve also only listened to the second half, which took evidence from Richard Lindzen, Donna Laframboise and Nicholas Lewis. These 3 would probably be regarded as on the skeptic side of the argument. This first half took evidence from Peter Stott, Brian Hoskins, and Myles Allen. If I get a chance, I’ll also listen to the first half.

I think it’s unfortunate that it was divided in the way that it was, in that it makes it seem as though the committee sees it as a debate of two halfs. If you think all 6 are experts, then why not simply divide them randomly. If this isn’t possible, or sensible, then maybe that says something in itself.

I’m actually finding it quite hard to summarise what was said. Donna Laframboise said very little and saying little about what she said, is probably the best option. She did say (and I paraphrase slightly) I’m a journalist with no scientific background whatsoever and that would appear to be consistent with the rest of what she said.

I found Richard Lindzen very unconvincing, which surprised me a little. I had thought he might come across in a much more convincing manner. Much of what he said was along the lines of there’s no evidence for alarm, or there is evidence that we have no need to be alarmed. Well, yes, it’s possible that the actual warming will be on the low end, but there’s a chance (and quite a good one) that it will be near the mean of the range, or higher. So, although there’s evidence that we have no need to be alarmed, there’s also evidence that we should be alarmed. He also made some statements about models not being good and that they didn’t have sufficient resolution. He also disputed the evidence for recent accelerations in sea level rise. Additionally, he suggested that the less bright students went into climate science, while the brightest went into physics and maths. I wonder what he thinks of the physicists and mathematicians who’ve become climate scientists.

He said something, though, that I think is either completely wrong, or poorly defined. He claimed, that if climate sensitivity is low (around 1oC) it will warm within a few years. If it’s high, it will take centuries. Hence, he seemed to conclude, that many decades will allow us to distinguish between low and high. Depending on precisely what he’s considering, if we are 1oC below equilibrium it will take decades to warm because of the inertia of the oceans. So, I think he’s wrong to say it will take a couple of years. Also, Otto et al. (2013) have used decades worth of observations to estimate climate sensivity, and the mean value for the equilibrium climate sensitivity is above 2oC.

I actually thought that Nicholas Lewis did quite well. I’ve described him as having the academic credentials of a good PhD student. However, he clearly has had a past career and his general expertise was evident. He seemed quite comfortable in front of the committee. I also think that what he presented was okay. He didn’t really say anything that I would outright dispute. He mentioned that estimates for the influence of aerosols has reduced since AR4 and that climate models are using aerosol forcings that are too high and hence they’re over-estimating the warming influence of CO2. This may well be a factor. He mentioned that the recent slowdown in surface warming may well simply be a consequence of natural variability. He, however, did make the rather standard climate scientists aren’t experts at statistics claim. I don’t know if this is true or not, but I’d be surprised if it was. Most scientific disciplines now have experts at statistics. There clearly are some who are not, but generalisations are rarely true.

The main thing he said that I would dispute is that climate sensitivity is likely 60% lower than that suggested by the models. I don’t know where he’s getting this from. The model trends are higher than observations suggest (by maybe 30%) and energy budget estimates are coming out lower than the model estimates. So, maybe there’s a 30% correction. However, already the energy budget estimates are rising as we refine our observations and we have paleo-climatological estimates that are consistent with the modelling estimates. Also, the mismatch between the models and the observations could be for many different reasons. So, yes the climate sensitivity could be lower than model estimates suggest, but – then again – maybe not.

So, that’s a rather quick summary as I’ve promised to clean the kitchen and make some soup. I may try and listen to some more and maybe write a bit more at a later stage. Then again, maybe I’ll have better things to do.

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59 Responses to IPCC 5th Assessment Review

  1. A quick comment. I thought Tim Yeo did really well as did some of the other members of the committee. Tim Yeo had a bit of a go at Richard Lindzen for being contradictory and someone else essentially suggested that Donna Laframboise was spreading conspiracy theories.

  2. BBD says:

    However, he clearly has had a past career and his general expertise was evident.

    As what? Did he say? He seems to have sprung from nowhere.

  3. BBD,
    He didn’t (or I didn’t hear). I’ve seen him described as a “semi-retired financier from Bath”.

  4. BBD says:

    That much I know – he lives about five hundred yards up the road from my sister-in-law 😉

    But beyond that – nothing.

  5. Vinny Burgoo says:

    Wotts #1, I caught only about 10 minutes of the ECC committee meeting but they included the part where you said Yeo ‘had a bit of a go at Richard Lindzen for being contradictory’ (I assume you mean the exchanges about whether the world has or has not just experienced the warmest decade in history) – and Yeo came across as deeply, deeply, shockingly deeply stupid. I know Tory MPs have that reputation but this was, for me, its first confirmation. How can a man who has risen so high in both business and politics not be able to grasp that saying you’re on a landing doesn’t mean you’re denying the stairs that got you there?

  6. Vinny,
    I disagree. Yeo asked Lindzen “have we just had the warmest decade on record” and Lindzen wouldn’t answer the question. There’s nothing wrong with that question. Lindzen could have simply answered “yes”.

  7. verytallguy says:

    to clean the kitchen and make some soup

    Marmalade for me, then I’m off for a couple of weeks. Get the Seville’s while you can! (I wonder what chemistry/physics explains pectin setting of jam?)

  8. dana1981 says:

    From what I’ve read, Lindzen did eventually admit that ‘of course’ it was the warmest decade on record, but it took a while for him to admit that obvious fact for some reason.

  9. Dana, it was a rather strange exchange. He was trying to argue that the question was ill-posed and illogical while (unless I’ve remembered incorrectly) it was pretty much as I said in my last comment. Easy question with an easy answer.

  10. I was listening to this in the background while I was working today (both halves), but missed lots and wasn’t paying attention much to the rest 😉

    What I heard Laframboise say was essentially the IPCC are incompetent and other stuff in that vein. I thought the large Scots guy on the committee did a good job of being, ahem, sceptical of the statements made by the 2nd panel, and made an interesting comment about the scientists doing the science and the politicians doing the policy. They [the 2nd panel] certainly seemed to be given a harder time too, but perhaps that was wishful thinking.

    Can’t comment on the technical side of things as, frankly, I don’t really spend much time trying to get my head around all the climate science issues.

    P.S. Prof. Phil Jones is giving a talk tomorrow at Edinburgh Uni on temperature records. Much to my annoyance, I have another engagement at the exact time of his talk! Bum…

  11. Reich.Eschhaus says:

    Why was Donna Laframboise flown in? Did she mention anything of importance? Why was she there? Does anyone know?

  12. Reich, I have no idea. At one point she was arguing that because the final changes are behind closed doors, we can’t trust what goes on. She was then asked something like “if there are scientists who’s work is mis-represented, why aren’t they complaining” and she had real answering that and similar questions. I thought she was very unconvincing and came across as unconvincing. I wonder if others will see it the same way.

    I should add that I had assumed that the committee had invited these people specifically so as to present a particular narrative. Overall, I thought the committee did a job and really challenged what Lindzen and Laframboise were saying. Of course, that does beg the question of why they bothered inviting the fringe element.

  13. dana1981 says:

    I saw a few people comment that whoever paid for Donna’s plane ticket wasted their money. Pretty much universal agreement that she didn’t add anything useful, as far as I saw. A lot of people could have told them that would be the case beforehand, of course.

  14. There was one other thing I had meant to mention in the post. Lindzen made an argument along the lines of “nothing the UK does will influence the UK’s climate. Acting because of climate change will damage your economy. Therefore you’re doing something that will damage your economy, but will have no effect on your climate.” I find this argument incredibly frustrating. Yes, if only the UK acts, it would be pointless. It’s a global issue. Secondly, it’s not obvious that acting will damage our economy. We’re importing an increasing fraction of our oil and gas. Renewables are getting cheaper. So, it may well be that we can adapt our economy without doing damage. Maybe not, but the assumption that it will obviously do damage is flawed, in my opinion at least.

    Anyway, I’m travelling today, so may not be commenting or moderating much.

  15. Barry Woods says:

    the point about the ‘warmest decade’, is that it is not a counter to the fact that that temperatures have slowed down or ‘paused’ for the last decade or so.. and that a lot of scientists are very interested to find out why.

    both are ‘true’. Yeo was being a bit silly on this

  16. Barry Woods says:

    Lindzen was not I think, not trying to not admit anything, he was perhaps just stunned by Yeo. trying to use the ‘warmest decade’ soundbite to counter the ‘pause’ (or slowdown) in the last decade (or so) when one does not contradict the other.

    (too many nots, ?)

  17. Barry,
    The issue I have with that argument was that Yeo didn’t preface his question. He simply asked (something like) “Has this been the warmest decade on record”. If that being true doesn’t mean anything either way, then a simple “yes” would be fine and one could move on and discuss the significance. I would argue that avoiding that question implies that it’s not regarded as insignificant. You could suggest that he had a reason for asking the question, but that doesn’t mean one shouldn’t give a straightforward answer.

    Also, warming hasn’t stopped. The slowest mean trend is 0.05oC per decade. Cowtan & Way suggest that including the Arctic increases this to something more than 0.1oC per decade. So, all the claims that surface warming have stopped are not correct. One could argue that the trends since 1998 (or some similar year) are not statistically significant, but that’s true for almost any similar time interval. If we want to use the statistically insignificant over the past 15 years argument as a reason for waiting, then we’ll never do anything until the trends exceed around 0.25oC per decade.

    So, Barry, what did you think of Donna L’s performance?

  18. Barry Woods says:

    Ref Donna – I think she was there to talk about the IPCC as a body & the process, and conduct in the media (so IAC stuff relevant) but most of what was discussed was off that topic. Lewis I thought seemed a little nervous at first? Lindzen was his usual self,

    Did you see him interviewed by Al Jazeera at Oxford Union, Myles Allen was there questioning/debating (as were D Rose and M Lynas) – still online – Head to Head – Medhir Hussain the interviewer. ( I sat next but one to Rose, and a young activist who went there to see a ‘sceptic’ shamed (and was disapointed. (she subsequently got invited to lunch with Prof Richard Betts, and Prof Jonathan JOnes)

    I actually found the first bit most interesting actually, less combative by Yeo and the others MP’s and some very good questions, Stott and Hoskins seemed very cautious to me?, and Myles was just Myles.

    Donna self funded her trip (via her tip jar) so no UK taxpayer was left out of pocket.

    I watched on TV, but met Donna, afterwards at a pub (organised in discussion thread at Bishop Hill)

    I know warming hasn’t ‘stopped’, but the rate has slowed to make it a serious area of scientific study, Yeo was obviously just trying a silly gotcha.. and it made him look silly. (and he came across as the worst sort of Tory cliche, he was better in the first half))

    maybe Tamsin should have a chat with him? 😉
    ref:

    Tamsin Edwards ‏@flimsin
    I wish people wouldn’t use “this is the warmest decade” as evidence that warming has not paused. Does not follow! http://www.bbc.co.uk/news/science-environment-24204323

  19. Barry Woods says:

    oops end of twitter conversation appeared, not the beginning.
    read it all here Anders and J Jones also contributed:

  20. Barry,

    I know warming hasn’t ‘stopped’, but the rate has slowed to make it a serious area of scientific study,

    Certainly, but given the continued rise in OHC it seems very unlikely that the slowdown in surface warming has any real implications with respect to overall global warming.

    Yeo was obviously just trying a silly gotcha.. and it made him look silly.

    It’s possible that he ended up looking silly, but the sames applies then to Lindzen for not simply answering the question. It wasn’t a particularly good exchange from either perspective.

    I didn’t see the Al Jazeera stuff at all.

  21. Barry,
    I know that it being the hottest decade on record does not mean that warming hasn’t paused. However, similarly, warming hasn’t paused so I wish people would stop saying it has. Plus, the statement “it’s been the hottest decade on record” is an entirely reasonably statement that can be backed up by actual evidence. I wish people would stop assuming that the person saying it is using it to imply that warming hasn’t paused. It could just be that it has been the hottest decade on record.

  22. guthrie says:

    Wait, so the old 30 year period to establish certainty about climate trends is now totally out the window and it’s okay to look at 5 years or less? Just how many climate scientists are commenting on this topic now, because at the moment there don’t seem to be any involved at all.

  23. Barry Woods says:

    you do agree that Yeo, was just trying a political gotcha though?
    it is worth considering that the current Met Office decadal projections allow the possibility that this decade, becomes the ‘second’ hottest on record.. 😉

    ref OHC – I know all the arguments, but GW (and AGW) has been framed as global surface temperature for decades, in light of the average MP understanding, it might take a while to get across top them the need to agree a OHC temp target?

    the point is, it should not be used to counter, that the temps have paused’ (slowed down, or whatever phrase you think) this is clearly what Yeo was trying to do… do you not think Yeo was doing exactly that.

    It HAS been the hottest decade on record..

    So what, that is merely proof of GW, should the next 2 decades cool slightly, then what?
    Even that would NOT disprove AGW.

    anyway, watch the first half, I’d like your impressions on that?

  24. Barry Woods says:

    I’ve got to go and sort out tax a bill and lots of other stuff, so may catch up this evening.

    but here is Lindzen at Oxford, even more laid back? (the interviewer was more aggressive) plus Lynas, Allen, Rose.
    http://www.aljazeera.com/programmes/headtohead/2013/06/201361311721241956.html

    please take into account at least an hour of material was edited out. (and there are some gaps, jumps and splicing going on) overall a fairly good edit though, some stuff was taken out, mainly perhaps so that the interviewer did not come across so badly..

    ie Prof Myles Allen complained about how the interviewer treated Lindzen in the comments at Bishop Hill the next day.

    Myles:
    “I was deeply embarrassed to be associated with Hasan’s ad hominem attacks on Dick Lindzen, in particular his going on about speaker fees and airline tickets. I thought this was going to be a discussion of climate science, and most of it seemed to be, as ever, about people and politics. As I hope I made clear when I had the chance, these were completely irrelevant to the discussion (and nothing he brought up seemed in any way exceptionable anyway) and that kind of attempt at personalising everything is just what is preventing a sensible discussion. I am very sorry that a visitor to Oxford was treated in this way.

    On the science side, I’m happy to accept that studies comparing simple models with observations of the recent record, of which several have been published recently, suggest a climate sensitivity in the region of 2 degrees (although this isn’t the only line of evidence). But even a two degree sensitivity, if we do decide to burn all available fossil carbon, which would take concentrations well over 1000ppm, would be more than enough for 4+ degrees of warming. The real question, therefore, is whether 4+ degrees is OK. That’s what we need to be discussing, and unfortunately, because once again it was side-tracked onto irrelevancies, the debate didn’t go there.” – Myles

    http://www.bishop-hill.net/blog/2013/3/9/lindzen-at-the-oxford-union.html
    Andrew Montford though the debate was worthwhile.

  25. Barry,

    you do agree that Yeo, was just trying a political gotcha though?

    Really? That’s probably what it’s all about anyway. I think he illustrated something interesting with how that question was received. Gotcha or not, it was revealing.

    I know all the arguments, but GW (and AGW) has been framed as global surface temperature for decades, in light of the average MP understanding, it might take a while to get across top them the need to agree a OHC temp target?

    Firstly, I’m not sure what this has got to do with science. Secondly, I’m not suggesting that we should switch from surface temperatures to ocean temperatures. We live on the surface. It’s clear that understanding how surface temperatures will evolve over the coming decades/century is important. My point about OHC is simply that claiming that the slowdown in surface warming somehow has major implications for AGW is wrong because the continued rise in OHC tells us the the climate system continues to gain energy, as expected from AGW theory. The slowdown may well have implications for TCR/ECS (we can’t rule that out) but it could also just be internal variability/aerosols. We should understand it, we just shouldn’t overplay the significance (either way).

    So what, that is merely proof of GW, should the next 2 decades cool slightly, then what?
    Even that would NOT disprove AGW.

    If the next 2 decades cool without there having been a major volcanic eruption or an asteroid strike, then it would have big implications. It’s very hard to see, if the radiative physics is correct, how we can continue to increase atmospheric CO2 concentrations without the surface warming in the coming decades. So, I actually disagree with you. If the next two decades cool slightly then I think that does have big implications and all those who argue for a low sensitivity would have a greater chance of being correct than they are now. Do I think it will happen? No.

  26. Guthrie,

    Wait, so the old 30 year period to establish certainty about climate trends is now totally out the window and it’s okay to look at 5 years or less? Just how many climate scientists are commenting on this topic now, because at the moment there don’t seem to be any involved at all.

    Yes, I agree. That was what I was trying (and maybe failing) to get at with my discussion of statistical significance in an earlier comment. However, we seem to fall into these traps quite easily (or I do). Scientists initially ignore the “slowdown” because we really need to consider longer periods than just a few years. Then they get criticised for not considering it. Then they do and all of a sudden it has a name like “the pause/hiatus”. Then if anyone mentions that it’s been the hottest decade on record, they get jumped on because that doesn’t mean anything (or disprove the pause) because surface warming has paused.

    We should probably be stressing more and more that the current short-term (decade/15 years) trend is still statistically consistent with the long-term trend. Therefore, there’s been no pause. Move on.

  27. We should probably be stressing more and more that the current short-term (decade/15 years) trend is still statistically consistent with the long-term trend. Therefore, there’s been no pause. Move on.

    Hear, hear!

  28. OPatrick says:

    Barry, do you think that Richard Lindzen should have answered ‘yes’ to the question of whether it has been the warmest decade? If not could you explain why not. You seem concerned that Tim Yeo, a politician, should be asking a politically motivated question, but presumably you don’t think that Lindzen should be making political judgements in his evidence.

  29. Barry Woods says:

    Lindzen did say yes, it is true, do you think Yeo understands the issues though?

  30. Barry Woods says:

    And if the ‘pause’ (global surface air temp’s that is) were to continue for 30 years 😉
    (political impacts?)

  31. Barry,
    Well, it took him a while. I realise that one of my first comments suggested that he hadn’t said yes. That was wrong. He did indeed say “of course” (I think) but it was the difficulty in extracting that that I thought interesting.

    Yes, I do think Yeo understands the issues, much better than I suspect you realise or are willing to acknowledge (I could be wrong about that though).

  32. Barry,

    And if the ‘pause’ (global surface air temp’s that is) were to continue for 30 years 😉

    If it were, there would be both scientific and political impacts. However, I don’t think you’ve ever explained why you think it’s possible that it could. Basic physics would suggest that it is somewhat unlikely given that we would have to then be sustaining a substantial energy imbalance without surface temperatures rising. Or, as I’ve said before, radiative physics is wrong. Is there any good reason why we should be betting on the long odds?

  33. OPatrick says:

    Barry – yes, I think Yeo understands the issues and wanted to show how reluctant Lindzen is to admit to anything that could be interpreted as showing that warming is continuing. Clearly Yeo is playing a political game, but he is dong so because he knew that Lindzen was likely to be doing so and was confirmed in that by Lindzen’s response.

  34. Barry,

    Donna self funded her trip (via her tip jar) so no UK taxpayer was left out of pocket.

    Really? I find that a little unfortunate. If we invite someone to present evidence to our parliament, we should pay – IMO at least. In fact, I would argue that they shouldn’t pay. They’re presenting evidence for our benefit not theirs. Of course there may be people that we think are not appropriate, but that doesn’t mean that they should then pay. It’s still the committee’s responsibility for inviting people and choosing who to invite.

  35. OPatrick says:

    And if the ‘pause’ (global surface air temp’s that is) were to continue for 30 years

    Presumably then it would likely represent a statistically significant deviation from the ongoing warming trend and would therefore become a pause rather than a ‘pause’.

  36. jp says:

    “It HAS been the hottest decade on record..
    So what, that is merely proof of GW,…”

    To a [Mod : minor edit] nothing will ever prove the “A” in AGW. They’ve had decades to show evidence for an alternative theory/mechanism but have come up with zilch. The temperature just goes up by itself; [Mod : minor edit] don’t have to provide an explanation for it, they know it just can’t be the CO2 that we produce.

    [Mod : since you were quoting someone who comments here and who comments politely and pleasantly, I’ve edited out a term that may cause offense. ]

  37. BBD says:

    And yet again, Barry Woods drips this meme into the conversation:

    So what, that is merely proof of GW, should the next 2 decades cool slightly, then what?

    And:

    And if the ‘pause’ (global surface air temp’s that is) were to continue for 30 years 😉
    (political impacts?)

    To which ATTP replied – yet again – with this:

    If it were, there would be both scientific and political impacts. However, I don’t think you’ve ever explained why you think it’s possible that it could. Basic physics would suggest that it is somewhat unlikely given that we would have to then be sustaining a substantial energy imbalance without surface temperatures rising. Or, as I’ve said before, radiative physics is wrong. Is there any good reason why we should be betting on the long odds?

    I have lost count of the number of times Barry has done this, and simply dodged questions from ATTP and others about whether this cooling is even possible, let alone remotely likely.

    I’m fed up with this behaviour.Can Barry please be *required* to provide a plausible physical mechanism for this endlessly-peddled cooling meme? Or can he be required to cease and desist?

  38. BBD,

    I’m fed up with this behaviour.Can Barry please be *required* to provide a plausible physical mechanism for this endlessly-peddled cooling meme?

    It would be nice Barry were to do that. Given the normal tone of the discussion, I’m probably cutting Barry a bit of slack because at least he remains pleasant (which I do value). Having said that, he hasn’t really presented anything that convinces me that he understands climate science (or the physics at least) particularly well. So it would be interesting to know if these relatively common utterances about extended pauses/hiati are motivated by wishful thinking or by a deeper understanding of a plausible physical mechanism.

  39. Barry Woods says:

    I pointed out that the Met Office decadal forecast had a range, that included cooling possibilty until the end of the decade..

    and the possibility of a 30 year ‘pause’ was raised my Dame Julia Slingo at the Royal Society event last year (she suggested PDO).

  40. BBD says:

    I don’t care what Slingo “suggested”, Barry. I want a physical mechanism by which the climate system might cool for the next two or three decades under increasing GHG forcing. I want to understand how the growing energy imbalance is overcome. Please explain the physical mechanism or cease to peddle this (IMO polemic) meme.

  41. Barry,
    But at BBD suggests, the problem is that if you really have cooling, then our energy imbalance can rise from 0.6 – 0.9 Wm-2 today to 1.5 – 2 Wm-2 in 15 years time. So, the oceans would need to be accruing energy at 3 x 1022 J per year. It seems physically implausible despite what Julia Slingo said. Do you at least accept this basic issue?

  42. Barry Woods says: “I pointed out that the Met Office decadal forecast had a range, that included cooling possibilty until the end of the decade.. ”

    There is always a probably that it will cool, there is also a probability that it will warm more than 0.4 °C, it depends on how large the probability is. Without giving numbers, the statement is hollow and not informative.

    If the temperature stay at this level for another 30 years, we will have much more confidence that the current temperature rise of 1 degree in the last century was not natural variability of some strange kind, but really man made climate change. And in that case, we would be lucky and may be making the transition to a renewable energy system fast enough, in spite of irrational opposition by the climate ostriches.

  43. Joshua says:

    Anders –

    >They’re presenting evidence for our benefit not theirs.

    While I wouldn’t disagree that they shouldn’t pay or that the basic rationale is public benefit – Donna may well benefit from this process also….

  44. I was surprised by Lindzen. For someone who is so hostile to climate models, he is remarkable keen to accept the results of economic models. And then give them a huge twist. Nordhaus has explicitly rejected Lindzen’s claim that we should wait 50 years that Lindzen bases on Nordhaus. The uncertainties on Tol’s net benefit to 2C are enormous, and acknowledged by Tol, Lindzen’s idea that it may be net benefit to 5C is mad.

    I’ve put a very partial transcript at http://quantpalaeo.wordpress.com/2014/01/29/well-all-be-dead-by-then-lindzen-in-london/

  45. BBD says:

    ATTP

    the problem is that if you really have cooling, then our energy imbalance can rise from 0.6 – 0.9 Wm-2 today to 1.5 – 2 Wm-2 in 15 years time. So, the oceans would need to be accruing energy at 3 x 10^22 J per year.

    Did you write an article on the rate of ocean heat uptake that would be required to stabilise GAT over the next decade or two? I can’t find it, and it might have been you in comments – sorry to have to ask – I can usually find things without too much fuss, but this is defeating me.

  46. Richard, thanks for the link to your post. I notice Paul Matthews has commented on your post and linked to his post about the attribution figure. He won’t listen to a word I say, but maybe you could explain why the error on the ANT bar in that figure is smaller than it would be if you simply determined it from the errors in GHG and OA. It’s not that complicated, so I’m surprised someone with his background and experience really can’t seem to work it out.

    What I find disappointing about Tol is that what he writes in his papers (those I’ve seen at least) is quite balanced and seems to acknowledge uncertainties. Publicly, however, he never seems to make that clear and seems to support people who claim that we have a net benefit for up to 2 degrees of warming. As you point out in your post, that may be true for the developed world, but likely is not for major parts of the developing world. Also, his 2009 paper has a typo that he seems unwilling to correct (the Hope 2005 value should be -0.9, not +0.9). Given that he seems to expect brutal and total honesty for climate scientists, he seems willing to skim over the errors/typos in his own papers.

  47. BBD,
    I wrote this one that worked out how long it would take the system to reach equilibrium if it were simply 1oC below equilibrium. I don’t know if it’s what you were looking for.

    It is the post I was thinking of when I pointed out that Lindzen was wrong when he said it would only take a few years to reach equilibrium if climate sensitivity is low.

  48. dana1981 says:

    The surface warming slowdown is a least in large part (probably mostly, IMO) due to internal variability (more efficient ocean heat uptake). Kevin Trenberth is an expert in this area (global energy imbalance, ‘hiatus’, ocean warming, etc.) and has pointed out in recent research that these sorts of events generally don’t last more than 25 years, and this particular slowdown event appears to have begun in 1998. So the surface warming slowdown will likely end within the next decade, and be replaced by accelerated surface warming.

    In fact, Trenberth co-authored a post on SkS today on this very subject.
    http://skepticalscience.com/warming-oceans-rising-sea-level-energy-imbalance-consistent.html

  49. Dana,
    Thanks. From what I know, I would largely agree. That does seem to be a plausible explanation for the slowdown (or, at least, a bit part of the explanation). I guess even another decade would be surprising given how the energy imbalance will grow if the slowdown were to continue that long.

  50. OPatrick says:

    Lindzen did say yes, it is true

    Having now listened to it I find that what Lindzen actually said was:
    “It’s entirely possible…”
    “Well, you know it’s always been a funny way of expressing things…”
    “The answer is if it was increasing until then and stopped…”
    “Yeah but I’m saying you’re imposing…”
    “Of course it is.”
    It took five repetitions of the question from Tim Yeo to get Lindzen to give a straightforward answer. I find it odd, Barry, that you would not be critical of a scientist giving scientific evidence for being so evasive. Surely someone in such a position should simply be giving honest answers to the questions. What would they have to fear? Do you think someone might take their words out of context and suggest they meant something different?

  51. Vinny Burgoo says:

    OPatrick, my interpretation of the exchange is that Yeo directed his question at nobody in particular, so none of the three witnesses answered immediately. After a couple of seconds, Lindzen gave a perfectly satisfactory answer (‘It’s entirely possible’) and started to elaborate. Yeo interrupted him and the spat went from there.

    Here’s an MP3 of the exchange (~750KB):

    http://www37.zippyshare.com/v/68267877/file.html

    (Immediately before Yeo’s question, Lewis had said something about bigger impacts arising from greater warming.)

    Lindzen evasive? Perhaps. But perhaps he was trying to save Yeo’s blushes.

    If so, he failed. What conceivable relevance to any surface temp hiatus could there be in Yeo’s clocked-speeding-at-90mph analogy?

  52. OPatrick says:

    No, ‘it’s entirely possible’ is not a perfectly satisfactory answer. The only satisfactory answer to the question is ‘yes’.

    Yeo’s speeding analogy was no doubt badly formed, but then he is not a scientific expert giving evidence in that capacity.

  53. dana1981 says:

    Answering “It’s entirely possible” to a question whose factual answer is “yes” is evasive unless you don’t actually know the answer to the question, which Lindzen did. Really he should have just said “yes, but the warming nevertheless stopped 16 years ago” (even though that’s not true, but that’s what he seems to believe).

  54. Reich.Eschhaus says:

    “I think she was there to talk about the IPCC as a body”

    What?

  55. Rachel says:

    I’m currently in the middle of rural Thailand and using a very slow and intermittent internet connection so I haven’t been able to listen to this other than Vinny’s link to the MP3 with Lindzen and Yeo (thanks, Vinny).

    I thought Yeo did a pretty good job. I do think the fact that this is the hottest decade on record is important and I think it is a reasonable response to someone who argues that global warming has stopped, although I was pleased to hear that this is not what Lindzen was saying.

    I think everyone here accepts that it is the long-term trend in global surface temperatures that is important rather than short-term fluctuations. So while this march up the stairs will contain periods of fast climbs and slow climbs, the fact that this is the hottest decade on record is some evidence that we are going climbing upstairs rather than down.

  56. BBD says:

    The problem isn’t Yeo; it is Lindzen. And no, this is not worth arguing about.

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