Sea level rise acceleration

You only have to look at the graph below showing sea level rise since 1880 to see that it has accelerated from about 1mm/year at the end of the 19th century to about 3mm/year at present.(from CSIRO).

CSIRO_GMSL_figure

If you take a closer look at recent sea level rise you’ll see that it has been very consistent, only deviating from the trend line by about 10mm at any time.

sl_ns_global

 

So if you were unscrupulous, and wanted to try to make it look like sea level rise had decelerated what could you do? You could split the series at a point where sea level was above the trend line and compare trends before and after.  this is what Klaus-Eckart Puls did (green line added by me):

Puls_1

Of course, you could achieve the opposite effect by splitting at  a point in time where sea level was below the trend line.  Note that the trend for the first half, 3.5mm/year isn’t significantly different from the overall trend and that the latest measurement lies on the trend fitted to the first part of the data (the green line above).

Naturally, Andrew Bolt was taken in, claiming that sea level rise was slowing, oblivious to the fact that this contradicted his earlier claims that sea level had stopped rising.

Comments

  1. #1 Neil White
    December 27, 2012

    Spangled Drongo:

    “The Alarmists would have it that the world’s weather, like a multihull, generally travells in a blissful state of Goldilocks comfort unles and until, hit by excessive [ACO2] force, reaches a tipping point from which it cannot recover and whammo! over it goes, down the gurgler. [positive feedback] ”

    You know even less about climate than you do about sea level. This is a truly remarkable state of affairs.

  2. #2 spangled drongo
    December 27, 2012

    So you deny that you believe in positive feedbacks then?

    You know even less about yourself than you do about the weather and SLs.

  3. #3 spangled drongo
    December 27, 2012

    You notice I didn’t say TIDES Neil. I’m still eagerly anticipating details of your expertise on tides.

  4. #4 Lotharsson
    December 27, 2012

    So you deny that you believe in positive feedbacks then?

    Hard not to unless you’re in abject denial. (Oh, wait…) There are a whole bunch of well-documented ones some of which are really obvious. And the earth would be a LOT cooler without them, which is pretty easy to demonstrate with basic physics.

    Then again, you seem awfully confused about what effects positive feedbacks have, as revealed by your deeply misguided portrayal of “What Alarmists would have it…”, so it’s entirely possible that there’s no-one here who believes in whatever it is that you are talking about.

  5. #5 bill
    December 27, 2012

    Your parochial homespun might impress then down at the local, dear Drongo, but, frankly, the fact that you’re desperately polishing some pearl with regard to some tidal inlet on the Gold Coast (whose geography you can’t even manage to get right) as if that’s going to disprove, um, the whole world, and, um, science, and then sneering at others for lacking your splendiferous nautical credentials – as if they had anything to do with anything and that you won’t elaborate anyway, no doubt because they’re over-inflated if not completely imaginary – only indicates how waaaaaay out of your depth you really are in the real world…

  6. #6 spangled drongo
    December 27, 2012

    And what are these common destabilising factors that grow exponentially to a runaway extreme and finally destroy the earth?

    Other than alarmists, that is.

    Or do you mean things like water vapour and clouds?

  7. #7 spangled drongo
    December 27, 2012

    And it is sad when one of your fav bed wetters recants:

    ‘I made a mistake': Gaia theory scientist James Lovelock admits he was ‘alarmist’ about the impact of climate change

  8. #8 spangled drongo
    December 27, 2012

    ‘waaaaaay out of your depth”

    Am I bill?

    In that case you should find it easy to refute any of my obs listed above.

    let’s have your pearls of wisdom, bill.

    Or can you only parrot others’ insults??

  9. #9 Stu
    December 27, 2012

    In that case you should find it easy to refute any of my obs listed above.

    Such as? You’ve been talking about boats and Gaia. You’re a pathetic, corner-bar level tone troll. Why do you feel you have put forth anything worth engaging?

  10. #10 Neil White
    December 27, 2012

    Spangled Drongo

    It is a remarkable leap to go from criticism of an incorrect statement that includes the phrase “positive feedback” to claiming that the person who wrote that criticism doesn’t believe in positive feedbacks.

    Unfortunately this is fairly typical of your level of argument.

    I’m not wasting any more time on you.

  11. #11 GSW
    December 27, 2012

    @Neil White

    “I’m not wasting any more time on you.”

    Fair enough Neil, a great loss for everyone I’m sure. Close the door on your way out.
    ;)

  12. #12 Stu
    December 27, 2012

    Wait, did Griselda just get dismissive? That’s precious.

  13. #13 spangled drongo
    December 27, 2012

    Stu the drive-by hit man.

    Either that or he can’t read.

    GSW,

    Bbbbbut Neil’s a TIDE EXPERT. We’re still waiting for his radiating, rationalising intellect to shine the light on our tangled pathway.

    He’s not leaving yet, surely?

  14. #14 Wow
    December 27, 2012

    Sorry, you seem to have left out the point.

  15. #15 bill
    December 27, 2012

    Wow, James Lovelock, at random! How long ago did we do that one? Running out of live ammo, eh? Rest assured, Drongo: I’m sure the IPCC will document all his important papers on the issue, just as they have in the past.

    Do you think you should perhaps seek out a forum somewhere to debate hull design and tidal influences on the Gold Coast? You seem to be demanding that this blog becomes one.

  16. #16 Stu
    December 27, 2012

    Oh, adding to the preciousness of the thread:

    And what are these common destabilising factors that grow exponentially to a runaway extreme and finally destroy the earth?

    OH HAI, spangled whatever. This is is what is commonly known in conversations amongst rational adults as a “straw man”. It means that you are attributing a viewpoint to your opponent that they actually do not hold.

    Or, and I shall attempt to use smaller words for your benefit, it’s you arguing against something nobody ever said, or would say, because it is stupid, and you hope really hard that nobody notices this juvenile tactic.

    Climate will not destroy the Earth. Nobody said that, as you damned well know. The only issue here is whether the climate can change sufficiently, and sufficiently rapidly, to make things really hard on billions of people.

    To be clear, this also means that the equally doltish “the climate changed before” is cute yet moronic. Yes, the atmosphere has held much more CO2 than it does now in the past.

    Are you a large fern, spangled? If not, that should worry you.

  17. #17 chameleon
    December 27, 2012

    Stu,
    And that little display of yours is also known as arguing with yourself.
    Would you care to explain why you think this is all about what you obviously believe is everyone else’s short comings?
    Your little rant here just basically argues if people don’t unquestionably believe in your view of the world then that automically follows they are mentally deficient.
    Not just a little ‘straw mannish’ in logic by any chance?

  18. #18 Stu
    December 27, 2012

    And that little display of yours is also known as arguing with yourself.

    I directly quoted you and refuted you. Obvious and stupid lie.

    Would you care to explain why you think this is all about what you obviously believe is everyone else’s short comings?

    You have been proven to argue in bad faith. You have been proven to be really bad at it. If there is an “all about”, you are more than welcome to BRING IT UP, MORON.

    Your little rant here just basically argues if people don’t unquestionably believe in your view of the world then that automically follows they are mentally deficient.

    Wow. Umm…

    This is is what is commonly known in conversations amongst rational adults as a “straw man”. It means that you are attributing a viewpoint to your opponent that they actually do not hold.

    Or, and I shall attempt to use smaller words for your benefit, it’s you arguing against something nobody ever said, or would say, because it is stupid, and you hope really hard that nobody notices this juvenile tactic.

    Thank you for doing the same thing again. Cutting and pasting saves a lot of time.

    I never called you mentally ill. I called you pathetic, I called you incompetent, and I called you stupid.

    You would not, by any chance, be someone on another thread coming in here under false pretenses, would you?

    Not just a little ‘straw mannish’ in logic by any chance?

    “Straw mannish in logic”? You have no idea what the hell a straw man fallacy is, do you precious?

    What is it about you deniers that prevents you from Googling even the most basic damned things? Are you that afraid of knowledge? Are you that insecure and delusional?

    Never mind. Don’t answer that.

    Still wondering whose sock puppet you are. I wish I had IP check rights on this site.

  19. #19 Stu
    December 27, 2012

    Of course, the para starting with “Your little rant here” should have been a quote. Edit feature, where art thou.

  20. #20 chek
    December 27, 2012

    Well that would be because you – that’s you, chameleon – haven’t managed to demonstrate a single correct understanding of real world data, and appear to be content to remain coasting on your admittedly impressive gargantuan ignorance, and then unsurprisingly find yourself left with nothing but tone trolling.

    It’s a lomg goodbye that really should ne nipped in the bud before any more pixels are inconvenienced.

  21. #21 chameleon
    December 27, 2012

    :-)
    Chuckle.
    You guys are truly funny.
    It has been a great education and great entertainment stumbling on this site :-)

  22. #22 chameleon
    December 28, 2012

    So Stu?
    Is that your way of trying to ask who I am or what I do?
    If it was, has it occured to you if you tried just simply politely asking that you may perhaps have a better chance of getting what you wish for?
    That may save you the time and energy required to obtain IP check rights. :-)
    As a little hint. I have never visited this site before last week. Neither am I a regular blogger anywhere else. I do however visit many different sites on recommendations from others and have rather eccelectic web site reading habits.
    I like to try and understand all points of view.
    I usually only comment when I percieve the behaviour is stifling any genuine debate.

  23. #23 spangled drongo
    December 28, 2012

    Stu, to get us all back on thread, were you capable of reading my claims on [lack of] SLR and do you have anything cogent to offer to refute them?

    Or would you prefer to waffle on about your [lack of] understanding of positive feedback.

    You see Stu, words like pos feedback and misogynist etc have certain meanings and you are stuck with them.

    Terribly unfair, I know, but as they say, you can have your own opinion but you can’t have your own facts.

  24. #24 spangled drongo
    December 28, 2012

    “Do you think you should perhaps seek out a forum somewhere to debate hull design and tidal influences”

    Bill, you poor old chap, you just don’t get it do you?

    Tidal obs and SLs is what this thread is all about.

    And my analogy of alarmists being all aboard a powered multihull with absolutely no self righting index [positive feedback] as introduced by your own Lernard Bernard as a standard by which other boats should be judged, and sceptics crewing a ballasted yacht with top category SRI [neg feedback] which is what I design and build and which said LB was casting aspersions on, probably went right over your tiny bird head.

    OH, the irony and the agony!

  25. #25 bill
    December 28, 2012

    Sigh – Dear Spangly Thingo,

    As I stated, your bizarre claim that the world climate system is self-regulating for our benefit is manifestly absurd, ahistoric, and probably a religious delusion, though, like your alleged nautical expertise, you remain coy on the matter.

    This thread is not about SLRs in a tiny localised region of your choice, the geography of which you cannot even get right in your own head. Nor is it about hull designs – their inefficacy even as an analogy has been dealt with above.

    You are well paired with your fellow-traveller Karen, who does not know which year this is.

  26. #26 spangled drongo
    December 28, 2012

    So when was the last tipping point, bill?

    When we last went irreversibly over the cliff?

    Y’know, like a multihull does when it capsizes?

  27. #27 spangled drongo
    December 28, 2012

    “This thread is not about SLRs in a tiny localised region of your choice, the geography of which you cannot even get right in your own head”

    When you seem to have the attention span of a gnat, bill, there is no point in repeating my claims but should you wish to go back and read them thereby getting your confused mind in focus, I will be happy to address any specific point you wish to make.

  28. #28 bill
    December 28, 2012

    How on earth can you conclude that I have a limited attention span from the above? How absurd! What the voices in your head keep telling you – jolly, salty tars all, no doubt – and what actual reality is don’t necessarily coincide, you know.

    We know from history that eras with CO2 level equivalent to current were very different to our own, and the CO2 level just keep rising, with each incremental upward tick separating us further from the benign late-Holocene that made us what we are. We also know that the abruptness of the transition to these higher levels is virtually unprecedented, and despite whatever the voices may be telling you – ‘Arrr, there, matey, as long as Sweet Baby Jesus is your Captain, you’d best believe he’ll always be steering you Right through the shoals of unpleasant reality’ – this is unlikely to result in anything good.

  29. #29 Lotharsson
    December 28, 2012

    You see Stu, words like pos feedback and misogynist etc have certain meanings and you are stuck with them.

    I’ve got my popcorn now.

    Spangled Drongo:

    1) Please define the term “positive feedback”.
    2) Please define the term “tipping point” in terms of “positive feedbacks” as understood by those you call “Alarmists”.
    3) Please give examples of “positive feedbacks” and “tipping points” as you think are understood by “Alarmists”
    4) Please cite the likely range of outcomes of those positive feedbacks and tipping points as understood by those “Alarmists”.

    There may be follow-up questions.

  30. #30 spangled drongo
    December 28, 2012

    Lotharsson,

    You are stuck with them because your Great Panjandrum Alarmist, AKA Whinnying Jimmy, invented them.

    Why should I define them for you?

    If you wish to recant, you will have to do a James Lovelock.

    Oh, the irony is exquisite!

    Now, what’re the follow ups?

  31. #31 spangled drongo
    December 28, 2012

    “How on earth can you conclude that I have a limited attention span from the above?”

    I know you really don’t want me to answer that bill, but a specific question on any one of my claims WOULD help me change my mind.

  32. #32 chameleon
    December 28, 2012

    Bill,
    what on earth do you mean by ‘virtually unprecedented’?
    It is either unprecedented or it isn’t.
    Lotharsson,
    Spangled is correct.
    There are plenty of accepted definitions of those terms supplied by what I’m guessing is what you perceive as your side of the political debate.
    That is just a guess BTW. Happy to be corrected about your political views.

  33. #33 spangled drongo
    December 28, 2012

    And bill, It would help if you answered some of my specific questions:

    So when was the last tipping point, bill?

    When we last went irreversibly over the cliff?

    Y’know, like a multihull does when it capsizes?

  34. #34 bill
    December 28, 2012

    Trollboy – ‘virtually unprecedented’ means there’s still some uncertainty as to just how fast some transitions may have occurred in the past.

    Spangly, you’re just asking the wrong questions.

    No matter how many semantic games one plays very abrupt transitions remain both uncommon and generally very bad for those organisms adapted to current regimes.

  35. #35 Lotharsson
    December 28, 2012

    You are stuck with them because your Great Panjandrum Alarmist, AKA Whinnying Jimmy, invented them.

    Good grief.

    Are you so abjectly stupid that you make a blatantly false claim that wouldn’t fool a five year old with a dictionary, or anyone who’s done any engineering course in about the last century?

    (And I don’t know who “Whinnying Jimmy” is in your mind.)

    Why should I define them for you?

    Because doing so will force you to demonstrate either that you do actually know what you’re talking about, despite the numerous misrepresentations and dubious claims you have made to date, or demonstrate that you don’t – as your ducking and weaving in response to my questions suggests.

    Now, what’re the follow ups?

    More illogic from you.

    You don’t get followups until you’ve answered the first set of questions. Declining to answer is not an answer.

  36. #36 Lotharsson
    December 28, 2012

    Spangled is correct.

    You may wish to rephrase that, or at the very least add some major qualifications. But that would require you grok what he claimed, and I strongly doubt you have.

    (And while I’m at it, don’t you have some concern and advice for Spangled Drongo re: his tone, frequent use of insults and infrequent ability to substantiate his claims and implications? Or are you not an equal opportunity advice giver?)

    Happy to be corrected about your political views.

    You are again making incorrect assumptions.

    My political views have zero to do with the well-known definition of “positive feedback” for example, a question for which there are no “sides”. The term was defined outside of climate science long before certain political views attempted to delegitimise its conclusions.

  37. #37 spangled drongo
    December 28, 2012

    They’re your little orphans Lothe.

    Your mate Whinnying Jimmy used them to the max to promote your ideology and his alarmism for the last 3 decades, YOU tell ME what they mean.

    When they were virtually unheard of prior to that in common weather and climate parlance, YOU tell ME what they do.

    When they have never occurred in the history of Climate Change, YOU tell ME what they are.

    Hint, take a cue from chickens as in coming home to roost.

  38. #38 Lotharsson
    December 28, 2012

    (While we’re at it, would someone please re-inform Spangled Drongo that, just as it was the last time, James Lovelock is still not a climate scientist, still was never revered or influential as one, his earlier (e.g. 2006-2009 vintage) views still did not form the past basis of the scientific case for concern (which arose years before that) and whatever his current views are they are still not evidence about the scientific case for concern?

    The comment about the IPCC including his climate science papers was clearly too subtle to get through.)

  39. #39 bill
    December 28, 2012

    Spangly, your true self is showing. You’re getting SHOUTY and INCOHERENT. And in mid-rant any pretence – and it is a pretence – of reasonableness simply drops away, doesn’t it?

    And who the hell is this ‘Whinnying Jimmy’? Is this some kind of pseudo-folksy, aw-shucks, Huck Finn, baffled-old-man attempt to abuse James Hansen, perhaps? Bizarre!

    And are you really saying that the climate has never reached a point where it has irreversibly shifted from one state to another? Surely you’re not really that stupid? Well, actually…

  40. #40 Lotharsson
    December 28, 2012

    …YOU tell ME what they do.

    That’s a pretty pathetic ducking and weaving attempt.

    I’ll take that as a strong admission that you’ve been using those terms to make assertions but you don’t actually know what they mean.

    And that’s odd, you having designed really successful boats and all. You give every sign of not knowing how to apply the concepts to a system which has feedbacks (even though one would imagine that the control systems for a boat would constitute such a system).

    You certainly haven’t been able to demonstrate a basic understanding of what different magnitudes of net positive feedback does to a system, let alone what happens when both positive and negative feedbacks are in play at once. This is even more odd because you seem so confident that scientists claim it must always lead to an “irreversible tipping point”. (Funny how you use the example of a boat tipping over as an irreversible tipping point though. I’m sure you’ve untipped a number of boats thereby reversing it, but you would have noted that it required a great deal of extra effort. Hmmm…..)

    Oh, and I still don’t know who “Whinnying Jimmy” is. Seems like you’d prefer to use insulting names than to be understood.

    Says a lot, really.

  41. #41 spangled drongo
    December 28, 2012

    “And who the hell is this ‘Whinnying Jimmy’?”

    Go on bill, have a wild stab.

    “And are you really saying that the climate has never reached a point where it has irreversibly shifted from one state to another?”

    And you can tell me about that too, bill, while you’re at it.

  42. #42 bill
    December 28, 2012

    I did have a ‘wild stab’! So you’re not even going to have the courtesy to simply state outright whether you’re abusing Jim Hansen? Has your analyst ever suggested that you’re manipulative at all, Drongo?

  43. #43 spangled drongo
    December 28, 2012

    They’re your babies Lothe, you define ‘em.

    “the example of a boat tipping over as an irreversible tipping point”

    You’re getting like bill, Lothe. Gnat’s attention span.

    That’s not what I said at all. I hope you haven’t got a job where lives depend on what you do.

    Have you ever seen a capsized multihull? It cannot recover without outside help. It does not self right and it can capsize relatively easily. A properly ballasted monohull OTOH will not remain in an inverted position. It self rights and it capsizes only with extreme force.

    Remind you of anything?

    Now, back on thread eh?

    You work out the difference.

  44. #44 bill
    December 28, 2012

    Wow! While I claim no expertise in psychology, I suspect there’s a whole conference worth of material in this one…

  45. #45 spangled drongo
    December 28, 2012

    ” While I claim no expertise in psychology”

    Well that’s a relief bill, as with SLs, you mean?

    And while you’at it bill, you could invoke Oliver Wendell Holmes’ last resort rule:

    If you’re stong on facts, pound the facts…etc

  46. #46 bill
    December 28, 2012

    Thanks for acknowledging that I’m strong on facts. Certainly true relative to you, but, then, that’s not really an achievement, is it?

  47. #47 spangled drongo
    December 28, 2012

    Bill, I simply left out the rest of the quote to take ie easy on you.

    You don’t even realise that what you’re in effect saying as per that quote is:

    “if you’ve got neither, pound the psychology.

    You’re a bit slow, bill love.

  48. #48 chameleon
    December 28, 2012

    So virtually means uncertain?
    I wasn’t trying to play semantics Bill.
    The term is a nonsense term.
    You supplied no evidence BTW it was just an absolute statement.
    Can I also ask how abrupt is very abrupt and also which organisms are suffering from this particular ‘virtually unprecedented’ phenomenon?
    Those sweeping statements sound very alarming.
    Lotharsson,
    Maybe you need to re read my post?
    I did explain the particular point that I believe was correct.
    Those terms have been widely used by the politics that surround CC.

  49. #49 bill
    December 28, 2012

    Oeer, the shame. Imagine having no interest in that quote! Funnily enough, I don’t feel the need to run ’round after your handwaving references, Spangly.

    Especially since, when asked simple direct questions – such as ‘Who the hell is Whinnying Jimmy?’ – you won’t respond, not even when subsequently asked specifically if you were referring to Hansen. It’s this kind of thing that makes me suspect you’ve got issues, frankly.

    Perhaps you were trying to spare yourself the embarrassment of revealing you’d referred to Lovelock in this ludicrous manner, given that: one; I’ve not heard him referred to as ‘Jim’, yet alone Jimmy, and, two; he is to Climate Science as Puccini is to the Delta Blues. Clearly my little ‘all his papers’ joke went straight over your head, but so many things do…

  50. #50 bill
    December 28, 2012

    And chameleon, you’re simply boring. Goodbye little troll.

  51. #51 spangled drongo
    December 28, 2012

    Bill, you’re not much good at pounding the psychology either.

    Better call it quits.

  52. #52 spangled drongo
    December 28, 2012

    Sorry bill, I missed where you first asked whether WJ was Hansen and yes of course he is.

  53. #53 Lotharsson
    December 28, 2012

    Maybe you need to re read my post?

    No, but maybe you need to read mine.

    At the point where you jumped into the interchange I had asked Spangled Drongo, whom you allege was correct (seemingly on this point), whether he could substantiate his claim that some (presumably) climate scientist that he will only refer to by a (presumably) insulting epithet had invented a certain term or two. I furthermore gave strong hints that one of the terms, if not both, was much older than that and had a widely accepted definition from common usage in other fields of studies.

    You attempted to redirect this to a discussion of terms used in politics which is not what I was talking about.

    And it’s worse than that. As far as I can see it’s not even what Spangled Drongo was claiming to be talking about. He seems to be referring to terms used in climate science by climate scientists, although it’s difficult to confirm this because he refuses to use people’s actual names or define the terms he’s using or give any citations.

    On the other hand it appears that he’s claiming to be virtually certain that the terms are applied incorrectly to the climate system – which is quite remarkable given that he clearly doesn’t know what they mean! Maybe you could give him some advice about not making assertions of virtual certainty when he doesn’t know what he’s talking about?

  54. #54 Vince Whirlwind
    December 28, 2012

    Crikey, Chameleon – you *do* realise you aren’t very smart, right? You can’t have got this far through life without realising that you aren’t really understanding a whole lot ofr what is going on around you.
    What makes you think your ignorant twitterings are any use here?

  55. #55 Lotharsson
    December 28, 2012

    So now Spangled Drongo has admitted he’s talking about Hansen’s use of “positive feedback” and “tipping point” and perhaps even “irreversible”, perhaps he can go one further and define the terms as used by Hansen?

    Or two further, and demonstrate his theory of the climate history of the earth which adequately explains the main observations without invoking “positive feedback” or “tipping point”? (“Snowball Earth” might be a good starting point. Or even merely looking at Milankovitch cycles.)

    After all, Spangled Drongo is asserting what chameleon might call an “absolute judgement” that they “…have never occurred in the history of Climate Change”, and since as we know “climate is always changing”, that means they’ve never occurred in the entire history of the earth.

    If that’s too hard, perhaps he can tell us what difference a positive feedback of 50% makes to the response of a system to a change in an input, compared to an otherwise identical system without the positive feedback? Ideally he would explain how this generates a “tipping point”, under what conditions a tipping point occurs, and what limits the effect of a positive feedback in a physical system.

    Nah, I predict he will sneer and name-call because that’s all he’s got. And I’m sure any day now chameleon will weigh in with deep concern about his tone hurting his case, right?

  56. #56 Lotharsson
    December 28, 2012

    Spangled Drongo’s obsession with Hansen and calling him alarmist for 3 decades is interesting, because Hansen’s 3 decade old predictions have turned out to be pretty decent using what is now considered a primitive climate model.

    IIRC an even earlier simpler model from the 60’s wasn’t bad – and it was much better than Spangled Drongo’s claim that climate is “self-correcting”.

  57. #57 spangled drongo
    December 28, 2012

    Good ol’ “pretty decent” Whinnying Jimmy. Only 150% wrong:

    http://wattsupwiththat.com/2012/06/15/james-hansens-climate-forecast-of-1988-a-whopping-150-wrong/

  58. #58 spangled drongo
    December 28, 2012

    Temperatures are lower than Hansen forecast they would have been even if humans had disappeared off the face of the earth in 2000.

    Scenario C was for essentially no emissions after 2000.

    http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf

  59. #59 Lotharsson
    December 28, 2012

    Some information for Spangled Drongo on claims that Hansen’s 1988 forecast was massively wrong.

    Summary: for anyone to make the claim that WUWT does, they first have to re-run the model with the forcings that eventuated, not the ones the model projected. The author of that WUWT article has massively cocked that up, and either dishonest or incompetent enough to continue with the claims. When you get the actual forcings right the model is about 20% too warm primarily because climate sensitivity was too high – which, when matched to observations implies a climate sensitivity well within the “concerning” range.

    Note carefully how (badly) WUWT fudges things to try to get their readers to follow along.

    1. Underneath the graph they talk about CO2 forcings since 2000 increasing at higher rates (“as much as 2.5%/yr”). They don’t say how they calculated this, nor even bother to inform their readers what the average increase was (whether under a linear or exponential increase model).

    2. They then claim this implies that total forcings have increased (by some amount). Note the bait and switch! The model includes a number of other forcings – some of which experienced strong reductions after the 1988 predictions were made (e.g. CFC reductions due to the Montreal Protocol).

    3. They claim that (1) – about CO2 increases since 2000 – implies total forcings since 1988 have increased “faster than scenario A” (which is an exponential increase) but they don’t substantiate it. Anyone sensing a potential problem with the extrapolation across two different dimensions here?

    4. They then calculate under these dubious assumptions an increase in temperature allegedly “predicted” by the model.

    5. They appear to calculate the “150%” figure by using endpoint differences rather than trends – a favourite of cherry-pickers everywhere.

    There are probably still other issues – but this should be enough. In other words, the authors are either lying to people who don’t know enough to tell the difference, or they don’t know enough to know when they’re making major analytical mistakes – and those in charge at WUWT went along with it (presumably for one of the same two reasons).

    And note how Spangled Drongo fell hook, line and sinker for it – despite some of the comments pointing out some of the errors. I reckon he’ll dismiss all of this or shift goalposts or throw a new red herring, of course.

  60. #60 Mike G
    Ft. Lauderdale
    December 28, 2012

    Please, lets do as Spangled Drongo suggests and return to the topic of SL rise… Like where he/she seems to be making the claim that some unnamed “experts” are telling him that mean high water has remained constant and the tidal range has merely been reduced worldwide. Please do tell SD, who are these experts and what is their exact area of expertise? Care to share with us their proposed mechanism by which the tidal range would be reduced since astronomical factors and coastal geomorphology are the two main determining factors of tidal range. If there are significant systematic changes in either of those that would seem to be quite “alarming.”

    I’m also interested in hearing more about your expertise on sea level data given that you didn’t even realize that this is freely available online from many countries’ oceanographic/ meteorological offices. That and the fact that you use strange terminology for basic concepts (eg. “half-tide”) almost gives one the impression that you aren’t that familiar with the subject matter and the people’s views you are parroting aren’t exactly experts either.

  61. #61 Lotharsson
    December 28, 2012

    Also note how Spangled Drongo has ignored the 1981 predictions which presumably are the ones he referred to when he described Hansen as an “Alarmist” for “3 decades”. Perhaps they were good enough that Drongo can’t argue they were “Alarmist!”?

    And do click on the “Advanced” tab in that link I posted in the previous comment. In particular look at Fig 2. which shows actual forcings since 1998 running BELOW SCENARIO B, not well above scenario A as claimed at WUWT.

    The great irony here is that the size of the error in the claim in the WUWT article is approximately 6-10x, which is far greater than the discrepancy in the 1988 model predictions. And yet Drongo will (likely) cling to the former as “more accurate” and call the latter “alarmist”.

  62. #62 Bernard J.
    December 28, 2012

    Distractions first:

    I would suggest that anyone who could possibly spend “a few years” on an iron clunker like “Eye of the Wind” with twin Caterpillar diesels that would make her go upwind like a witch [koff], isn’t really into the who’s who and what’s what of sailing.

    Drongo, he travelled around the world a number of times, during which he sailed on many other vessels and took part in many tall-ship events and – like you apparently – races. He’s skippered/captained everything from fishing boats to yachts to schooners to freighters. But the fact that you’re acquainted with the Eye implies that its background also is not unknown to you, so you should have some idea of the type of sailers who have crewed her. They’re certainly not exclusively “iron clunker” types… although some, I suspect, would love to pursuade you of the error of your disparaging ways by inviting you to clean the keel whilst handily tethered to a length of rope looped around the hull….

    And my analogy of alarmists being all aboard a powered multihull with absolutely no self righting index [positive feedback] as introduced by your own Lernard Bernard as a standard by which other boats should be judged, and sceptics crewing a ballasted yacht with top category SRI [neg feedback] which is what I design and build and which said LB was casting aspersions on, probably went right over your tiny bird head.

    Let’s not go too far sideways into one of your shoals of red herrings. I asked you to elaborate on your design/building experience in order to ascertain exactly from where you are coming in terms of your understanding of riverine hydrology and marine oceanography. So far you’ve supplied nothing to buttress your claim of decreasing riverine king tide height as a proxy for global sea level. Instead you fixate on the relative stability of multihulls – a straw man gambit typical of the sort you are wont to employ.

    But before we leave your diversion…

    Have you ever seen a capsized multihull? It cannot recover without outside help. It does not self right and it can capsize relatively easily. A properly ballasted monohull OTOH will not remain in an inverted position. It self rights and it capsizes only with extreme force.

    Remind you of anything?

    Yes, the planet’s climate. But as others have observed, in diametric opposition to the spin you placed on it.

    The climate, pushed out of whack by a forcing equivalent to as much CO2 as humans are emitting, does not simply “roll back” after a couple of years to its Holocene mean. If you have some science though that says otherwise please share it. However, as I have said before, be prepared to defend yourself – in doing so you will have to explain why the planet has transitted between glacial maxima and minima for the last 2.6 million years in response to fluctuating forcings, rather than hanging around the pleasant, narrow Holocene temperature range in which human cultures as we known them developed.

    Hardly a self-righting “monohull”-type of pattern, that, especially on the time-scale relevant to the preservation of a climate conducive to human society and perhaps even to human ecophysiology… In fact, given the countering forcings and forcing-related phenomena that are required to reverse from a maximum or a minimum, I’d say that a multihull metaphor is most apt.

    But enough of that. If you’ve mucked around with lifting-keels yourself you should have at least some passing familiarity with hydraulics. It surprises me then that you once said (on 22 February 2010 to be precise):

    At my benchmark the ’74 flood was about 1.5 metres above the king tide mark and the current was still running UPSTREAM at its peak. IOW this rise was possibly all due to the cyclone and sea surge. Not the flood.

    Do you seriously not understand how a strong surge can interact with a riverine flood and still run upstream?!

    Really? Seriously?! Are you claiming that this is not possible?

    Let’s just summarise your position.

    1. You have a mark on a sea wall in a river about 7 kilometres from the nearest mouth to open ocean.

    2. You claim that this mark indicates higher king tide levels in the 70s compared to recent times, although you provide no testable substantiation of this.

    3. Notwithstanding points 1 and 2, you claim that professional oceanographers are wrong in their assessment that global sea level is increasing.

    4. In the process of making your claim as described in point 3, you have presented no evidence that you have accounted for the modifying impacts of dredging, of riverbank alteration, of mouth modification, of significant canal estate developments, and of other riverine structural alterations that affect the Gauckler–Manning parameters that in turn affect tide height/water depth in rivers.

    5. In the process of making your claim as described in point 3, you have presented no evidence that you have accounted for the modifying impacts of barometric pressure history over the period that you claim riverine king tides have declined.

    6. In the process of making your claim as described in point 3, you have presented no evidence that you have accounted for the modifying impacts of onshore current characteristics over the period that you claim riverine king tides have declined.

    7. In the process of making your claim as described in point 3, you have presented no evidence that you have accounted for the modifying impacts of the extensive upstream damming of the Nerang River over the period that you claim riverine king tides have declined.

    8. In the process of making your claim as described in point 3, you have presented no evidence that you have accounted for the fact that the two nearest tide gauges, at Brisbane and at the Gold Coast, indicate no decline in overall sea levels, and in fact demonstrate the opposite – that sea level is increasing.

    9. Throught the 3 year history of your unsubstantiated slandering of professional oceanographers, you have repeated your claim without any scientific evidence at all, and without demonstrating that you even understand the complexities of riverine hydrology or of sea level dynamics.

    10. Throught the 3 year history of your unsubstantiated slandering of professional oceanographers, you have steadfastly refused to answer the many, many questions put to you that attempt to clarify your understanding, and that attempt to address serious flaws in the understanding that you present, such as your attempt to apply linear regression to periodically oscillating phenomena.

    You’ve been bleating about your bloody river wall for nigh on three years Drongo. When are you going to start applying science to what is no more than an untested anecdote? And when are you going to address the multiple scientific counters that render completely irrelevant that anecdote even if it could be fully substantiated?

  63. #63 Bernard J.
    December 28, 2012

    Throughout…

  64. #64 Bolt for PM
    December 28, 2012

    I return today to briefly cast my eye over this thread after a pleasant Christmas break. I hope you all had a happy and peaceful Christmas.

    Unfortunately I just haven’t the free time to follow all of the discussions and various links, I have no idea how you all manage to do that. You either have a lot of free time or stay awake a lot longer than I do.

    Now, all I can see since I was here last is an awful lot of arm waving and diversions. But if I can try to summarise.

    The original post argues that sea level is clearly accelerating and shows several graphs to confirm this. Spangled Drongo noted that his local sea level does not appear to reflect that. I noted that that was a similar situation from what I could see of my own locale. I also suggested that the said graphs actually show me that SLR has not accelerated in the past 70 years. And in fact, the past 10 years or so show a deceleration, a trend shared by the global temperature anomaly. Various really smart folk have then spent lots of time and words shooting down these thoughts with much reference to graphs, papers, other blog posts and so on.

    Now, the funny thing is that the real question seems to have disappeared from the discussion. SD is simply saying that where he is, there is little sign of any SLR. In the real world. I have observed a similar thing. The question then is, what real world observations back up a claim of accelerating SLR? I mean, what physical on the ground effects are we seeing? So far, no-one has advanced any evidence.

    Someone earlier (was it Bernard J) trotted out some graphs of tide heights for Brisbane and Gold Coast, which, try as I might, didn’t seem to me to be a ringing endorsement for accelerating SLR. Actually I think they did more for SD’s cause but I guess that’s just my denialist take on things, huh?

    But come on, someone somewhere must have some physical evidence of real world effects of SLR over the past century. I’d prefer Australia, but anywhere is OK.

  65. #65 Wow
    December 28, 2012

    “Spangled Drongo noted that his local sea level does not appear to reflect that”

    You seem to be forgetting that he’s not near an ocean, therefore local measures cannot be measuring SEA LEVEL RISE.

    You seem very busy if you missed that out.

    Far too busy to take your valuable time to post here.

    I would suggest you wait until you have time to read glittery bollocks’ posts before making statements and asking questions already answered.

  66. #66 bill
    December 28, 2012

    Thanks for that very neat and thorough summary, Bernard.

    Turns out we have developed this thing we call ‘science’ specifically so we are not misled by the parochial, anecdotal, and incidental, Spangly.

  67. #67 Bolt for PM
    December 28, 2012

    “You seem to be forgetting that he’s not near an ocean, therefore local measures cannot be measuring SEA LEVEL RISE.”

    No I did read that, though not with enough depth I’ll grant you. But regardless of all of those confounding additional factors, one would imagine that SLR should still impact at some point.

    In fact, that goes directly to the nub of my question. Surely there must be an actual physical impact from SLR. Various local factors can’t constantly mask those can they? If they do, then what concern should we express for a SLR that doesn’t actually DO anything?

    SD makes a fair point regardless of the charges against him. Where he is, SLR has had little appreciable impact. You seem to agree with this by the very lengthy detailed arguments as to why local river conditions will not reflect the SLR discussed. So, if his location can’t show SLR where does? And when can we expect SLR to overwhelm these local conditions? After all, it hasn’t happened for 70 years so far…

    And yes, my time is far too valuable to spend here but you seem like such a nice bunch.

  68. #68 Wow
    December 28, 2012

    “one would imagine that SLR should still impact at some point.”

    Only if one wanted to imagine such. One would have no reason to do so though, unless one wished to pretend something that had no basis in reality.

    “In fact, that goes directly to the nub of my question. Surely there must be an actual physical impact from SLR”

    Hurricane Sandy.

  69. #69 Bolt for PM
    December 28, 2012

    “Only if one wanted to imagine such. One would have no reason to do so though, unless one wished to pretend something that had no basis in reality.”

    Oh… how silly of me. So one need not imagine that SLR will have an impact? So this is all just a theoretical exercise? No need for all those silly council by-laws based on the impacts of a future SLR? Damn, i missed that.

    Hurricane Sandy. that it, eh? Your smoking gun. Excuse me while I recover from another round of side-splitting mirth.

  70. #70 chameleon
    December 28, 2012

    As several have pointed out there seems to be a lot of arm waving and not much supplied evidence.
    I have not had much luck trying to paste links from my samsung tablet but will attempt again now I am at my office computer.
    Last time I tried to paste it was a dismal fail.
    These links are links to graph reps of observations similar to the ones above.
    Interestingly, they show different conclusions.
    There is nothing inherently wrong with the source of the data and the methodology has been clearly outlined.
    As with the graphs above, they are a ‘snapshot’ representation of the available data. I neither absolutely believe them and/or disbelieve them.
    I think they’re all useful to help us understand the world around us.
    I do not believe they should be used in the manner that the politics are using some of them currently.
    I also will re iterate that they bear similarities (though not exact sameness) to other models that are used to help us understand the world around us.
    They are indeed useful tools, but they should not be considered prophetic (IMHO)
    I hope it works this time.
    http://www.climate4you.com/Text/Climate4you_June_2012.pdf
    http://kenskingdom.wordpress.com/2012/05/14/acorn-sat-a-preliminary-assessment/
    http://www.climate4you.com/Text/Climate4you_February_2012.pdf
    http://www.real-science.com/wp-content/uploads/2012/01/image277-1.gif
    Of course there are many more of these all over the place and they all reach varying conclusions, which was the point that I was trying to make earlier and which I think Tim also highlighted…although he did choose to call it unscrupulous.
    Based on the data they use and the assumptions about the relationships between the variables….they are correct for those circumstances at those moments….however their projective capabilities are not set in stone because those relationships can change quite remarkably.
    It appears from data collected over the last 10+ years that the correlation between ACO2 and SLR is not as definite as was originally hypothesised.

  71. #71 Wow
    December 28, 2012

    “So one need not imagine that SLR will have an impact?”

    On rivers far inland?

    No, one should not find themselves imagining that river levels have any bearing on sea level rises nor the other way round.

    One should also make clear what one is talking about when one uses the indefinite article in a continuing statement sentence that is preceeded by two nouns that could be the indirectly asserted indefinite article.

    If one wished to maintain honesty.

    “No need for all those silly council by-laws based on the impacts of a future SLR?”

    What council bylaws are you referring to? They would have nothing to say about RIVER LEVELS, if they are about SEA LEVELS right?

    Or is one being deliberately obscure so as to score ” talking points”?

    One things one is doing so.

    “Hurricane Sandy. that it, eh?”

    You asked for one.

    There is one.

    And if one were honestly enquiring about such events, one would be satisfied that one had been promulgated to one and assess the assertion.

    But one is not being honest, are you.

  72. #72 Wow
    December 28, 2012

    “Of course there are many more of these all over the place and they all reach varying conclusions”

    Of course, you have access to Acorn et al’s raw data right? And the modifications of that data, right? And they HAVE assessed UHI and siting errors, right? And you have checked this, correct?

    No, you wish to pretend that Australia is the entire world, that some unknown dataset is correct and that the entire world is not subservient to the physical realities, right?

    PS wasn’t some numbnuts recently going on about how nobody denied it was warming? Yet here is chammy giving a link to someone who claims there has been no warming, even a cooling.

  73. #73 chameleon
    December 28, 2012

    Ummmm,Wow?
    Some of that work I posted comes from Norway.
    Maybe you should actually read it first?
    I also didn’t say that I agreed/disagreed with any of the conclusions.So I have no wish to pretend anything of the sort.
    If you can prove that there is something wrong with the actual data sets that were used and/or the methodology I am all ears.
    Other than that you still seem to be doing a champion job of missing the point.

  74. #74 Wow
    December 28, 2012

    “Some of that work I posted comes from Norway.”

    Ummm, So?

    “Maybe you should actually read it first?”

    Hey, you first!

    From your acorn link:

    “In March, a new daily temperature reconstruction was released, called the Australian Climate Observations Reference Network- Surface Air Temperatures, or ACORN-SAT (Acorn)”

    Did you notice the “ASUTRALIAN” there?

    Did you?

    Or did you not read it at all?

    “If you can prove that there is something wrong with the actual data sets that were used and/or the methodology I am all ears.”

    They would need to release that information first.

    But one thing I CAN say definitely is wrong with their data: It’s ONLY AUSTRALIA.

    Big though it is, it isn’t the globe.

  75. #75 Lotharsson
    December 29, 2012

    Chameleon, you might try posting links to reputable sources of scientific information if you want to be taken seriously.

    As just one example, anyone with a modicum of scientific literacy who spends more than a minute at real-science.com will quickly conclude that the posters are cranks who don’t know what they are talking about. (UFOs, the future 50 billion population of the earth, the NOAA has been faking temperature records for 840 months in a row I tell you because only the raw data is accurate!, Stephen Goddard’s astonishingly inaccurate understanding of Arctic ice, a beautiful example of how to mislead the gullible by stretching the y-axis – and that’s just from a quick skim of the first page.)

    That’s why people here generally want to see peer-reviewed papers and the kinds of data sources that meet the bar for peer reviewed publication. That’s why – as you point out – you can find all sorts of opinions on scientific questions if you scour the Internet, but not all opinions have equal scientific merit.

    Did you not learn anything from Spangled Drongo’s post to a non-peer reviewed article at WUWT claiming that Hansen’s peer reviewed predictions from 1988 had overestimated warming by 150%, when only a small amount of analysis was required to show that it was only about 15-20%? Do you not understand that the WUWT “analysis” would have been immediately rejected for egregious error had it been submitted to a peer-reviewed journal?

    By posting a link to real-science.com – which appears to be at least as bad at science as WUWT – you demonstrate very clearly that you don’t have the requisite scientific skills to determine when someone is promoting false scientific claims. Interestingly the climate4you.com website states as its objective that it “…assist[s] reflective people to form a personal opinion on meteorological and climate matters”. What kind of scientific merit do you think should be attached to the personal opinions of reflective people whose reflections still leave them unable to sift the most basic pseudo-scientific bullshit from actual science?

  76. #76 Lotharsson
    December 29, 2012

    Let’s take just one of your (frequently reiterated?) claims:

    It appears from data collected over the last 10+ years that the correlation between ACO2 and SLR is not as definite as was originally hypothesised.

    Perhaps you should start – as Spangled Drongo refuses to – by specifying what you understand the climate science says about it.

    1) Specify the definition of ACO2 as used by mainstream climate science
    2) Specify the definition of SLR as used by mainstream climate science
    3) Specify the relationship that mainstream climate science claims between (that definition of) ACO2 and (that definition of) SLR. In particular, as found in your claim, please define the expected correlation between (that definition of) ACO2 and (that definition of) SLR. And in order to fully clarify your claim please define the term “definiteness” of correlation and specify what definiteness is attached to the ACO2/SLR correlation by mainstream climate science.

    Cite references please. That should be easy – the IPCC AR4 report is online, searchable, and report name + page numbers are acceptable should you prefer.

    Once you’ve done that we can discuss whether the data merit your claim that the correlation “isn’t as definite” as previously hypothesized.

  77. #77 spangled drongo
    December 29, 2012

    BJ, you hand-waving simpleton, you still don’t choose to understand that an upturned multihull is the result of positive feedback. An unrecoverable situation that the world’s climate has never entered whereas a self righting system is what we have or we wouldn’t be here.

    Now even you may have noticed while sipping absinthe on your balcony that the Gold Coast is essentially a flood plain. The Nerang estuary has the same tide range as the Broadwater and with the Seaway construction it also got lower low tides and higher high tides however the highest high tides are still lower than they were ~50 years ago.

    Are you seriously inferring that dam construction would reduce these estuary and SLs?

    As well as dredging entrances?

    Just think of the govt grants you could get for this and solve the world’s problems at the same time. You may have stumbled on something here, but probably just stumbled is nearer the mark.

    If you had paid attention BJ, you would have seen that this is just ONE of many benchmarks on SLs that I have accrued over ~70 years and they all agree. For example, the house I lived in at Cleveland Point in 1946 where the highest tides covered the lawn and threatened to run into the well we had just dug that was our only water supply, forcing us to quickly put a levy bank around it. The highest tides today are ~ 30 cms lower yet the landscaping is still the same and the well is still there.

    My grandfather owned the Woody Point Jetty store and flats and I spent WW2 there where high tides also came up on the lawn. On the remaining original lawn today that doesn’t happen by ~ the same 30cms.

    I also have many friends who have spent their lives by the sea in sea-front houses and sea-front businesses with sea-front infrastructure, who naturally pay great attention to the world’s concern with climate change and SLR and who are aware of what it entails for them much more than the average person and while many of them don’t measure the high tides to the last millimetre, they invariably tell me that the highest tides are no higher than they ever were in their experience.

    And my benchmarks also agree with the few tide gauges that go back that far.

    BJ, the only advice I can offer is that you mend your ways by coming down from your lofty balcony, cutting back on the absinthe, interacting with the real world and making a few personal observances for yourself while you still can.

    The only advance you have achieved from this debate is that you are now waving and drowning at the same time.

  78. #78 Lotharsson
    December 29, 2012

    I’ve just had a quick skim through a climate4you.com “report”. It’s … about as bad as what you’d expect someone making the claims chameleon is making to rely upon.

    Far from the website’s stated objective of presenting the data and allowing people to form their own opinions, it takes well-known data sets and layers its own interpretation over the top using such well known tactics as (I kid you not) Curtin’s “5th order polynomial fit” (the June report, p24, fitted to 20 years of HadCRUT3). They claim that the 5th order and accompanying linear trend are shown to “clearly demonstrate[] the differences between two often used statistical approaches to determine recent temperature trends.”, and they point readers to the R^2 values. They slyly add a disclaimer “…that such fits only attempt to describe the past, and usually have little predictive power.”

    There’s also the presumption on p22/23 from very dubious arguments about the length of time it was warming before the IPCC was established that “…it may safely be concluded that 10 years was considered a period long enough to demonstrate the effect of increasing atmospheric CO2 on global temperatures.” This is used to “justify” – and I use scare-quotes advisedly – some unspecified procedure which assigns to 10 or more year periods on a CO2 and temperature graph a “positive” or “negative” relationship between temperature and CO2. There is (a little earlier) some lip service given to the point that other factors influence temperature over short periods, but instead of using well-known procedures for testing their claims, they avoid any test for statistical significance (of course) and do not even specify the procedure they used for choosing the breakpoints between “positive” and “negative” time periods.

    They show surface temperature anomalies on p1 – but against the very unusual choice of baseline period = 1998-2006. Three guesses for why they chose a baseline too short to qualify as climate, starting in one of the warmest years ever!

    They show ocean heat content to 700m (p10), but not to 2000m. Three more guesses why. On p16 they show sea ice extent – but total, NOT anomalies (for chameleon’s benefit this makes the trend far harder to see); on p17 they show a snapshot of Arctic sea ice thickness but not history/trend, and they CERTAINLY don’t show any sea ice volume history/trend. It’s almost like they know which charts to leave out in order to give a certain impression.

    I haven’t gone through all of the graphs – who knows what other tricks they have used to bias the uninformed reader.

    Oh, and p18 gives a SLR graph showing pretty much a steadily continuing trend. I wonder how chameleon plans to argue that it shows that the “hypothesised correlation isn’t as definite”? Perhaps he’s going to try using the accompanying “simple empirical forecast [apparently an extrapolation] of sea level rise by 2100″ which predicts 18cm using a method they don’t specify, although they are much more willing to say which dataset they used – presumably in an attempt to bask in reflected credibility, or maybe even in the hope that readers will think the “forecast” is from the same source.

  79. #79 David B. Benson
    December 29, 2012

    Lotharsson seems to be doing a good job of troll whaking.

    http://policelink.monster.com/products/products/1390-troll-whacking-staff-

  80. #80 Lotharsson
    December 29, 2012

    …you still don’t choose to understand that an upturned multihull is the result of positive feedback.

    I’m not seeing that.

    You, on the other hand, still won’t even define positive feedback, let alone demonstrate that you have the first clue what scientists say about it with respect to the climate. And leaving climate aside, you are operating from fundamental misconceptions about what positive feedback means for a system.

    Since you determinedly refuse to answer more abstract questions that would help you learn, how about we try it with your preferred subject.

    1) Under what circumstances does a multihull remain upright?

    2) In your understanding, does the fact that it remains upright under those circumstances mean that positive feedback or negative feedback is at work?

  81. #81 Bolt for PM
    December 29, 2012

    Wow:
    “So one need not imagine that SLR will have an impact?

    On rivers far inland?

    No, one should not find themselves imagining that river levels have any bearing on sea level rises nor the other way round.

    One should also make clear what one is talking about when one uses the indefinite article in a continuing statement sentence that is preceeded by two nouns that could be the indirectly asserted indefinite article.

    If one wished to maintain honesty.

    No need for all those silly council by-laws based on the impacts of a future SLR?

    What council bylaws are you referring to? They would have nothing to say about RIVER LEVELS, if they are about SEA LEVELS right?”

    Wow, SD’s claimed benchmark is not on a river far inland, it is relatively close to the river’s mouth and it’s affected by tides. Now, perhaps it is largely invalidated by all of the effects others have noted, but SD backs up by observing similar trends elsewhere. My own anecdotal obs from nearby over 50 years match. I am not saying this is definitive evidence one way or the other, but it IS real world observation that despite the global trends in the graphs shown earlier in this post, there is little real world evidence of this that I have seen. But perhaps there is. So cite it.

    Hurricane Sandy – perhaps sea levels had an effect, but there are far too many other factors to use this as an arguing point. As the data I posted earlier shows, there have been similar tidal surges in the region and it is even suggested that there have been higher ones in historic times. That extreme events can cause new records is not an indicator of a broader trend or effect. If we could clearly observe a more typical storm in the region evoking an unusual response, then yes we’d have a case. Or so it seems to me. Now maybe that’s happening, but I’ve not read of it. But always keen to see such empirical evidence.

    The rest of that post of yours is just more arm waving. Who cares about indefinite articles preceded by swinging participular nouns? The underlying point that you don’t wish to tackle is simple. Show me some clear evidence of real world effects caused by SLR on the Australian coastline. All we’ve got so far is complaints that SD doesn’t have the smarts to properly assess the data, and some rather unsupportive tide data from nearby gauges which as far as I can tell seem to support his case.

  82. #82 Bolt for PM
    December 29, 2012

    “All we’ve got so far is complaints that SD doesn’t have the smarts to properly assess the data, and some rather unsupportive tide data from nearby gauges which as far as I can tell seem to support his case.”

    Alright, it’s a crap sentence. What I mean is that the tide gauge data offered up as evidence of SLR doesn’t seem to do that from my perspective.

  83. #83 spangled drongo
    December 29, 2012

    Lothe, If you haven’t the faintest idea, and you haven’t, dont comment.

    Just stay on thread instead.

  84. #84 spangled drongo
    December 29, 2012
  85. #85 Bernard J.
    December 29, 2012

    Blot for PM.

    With respect to your comment about Drongo’s denial of sea level rise…

    Spangled Drongo noted that his local sea river level does not appear to reflect that.

    Fixed that for you.

    I noted that that was a similar situation from what I could see of my own locale.

    Data? Evidence? Records of histories of relevant hydrodynamic/hydrological parameters?

    I also suggested that the said graphs actually show me that SLR has not accelerated in the past 70 years. And in fact, the past 10 years or so show a deceleration, a trend shared by the global temperature anomaly.

    At my local jetty the sea level was a metre lower around 6:00 am this morning than it was just after midnight. Ergo sea level rise is accelerating…*

    Now, all I can see since I was here last is an awful lot of arm waving and diversions.

    Yes, but that has always been Drongo’s modus operandi. If he actually addressed any of the points put to him, his only subsequent option would be to concede that he is wrong.

    Someone earlier (was it Bernard J) trotted out some graphs of tide heights for Brisbane and Gold Coast, which, try as I might, didn’t seem to me to be a ringing endorsement for accelerating SLR. Actually I think they did more for SD’s cause but I guess that’s just my denialist take on things, huh?SD is simply saying that where he is, there is little sign of any SLR.

    The same situation likely exists for anyone else located on a highly-modified river at least 7 kilometres from an opening to the open ocean. Drongo likes to call the Broadwater open ocean, but he should recall that he once referred to it as a stilling pond which should give him a clue about its effect on marine hydrodynamics (and disregarding relevant changes to riverine hydrology/hydrodynamics)…

    “You seem to be forgetting that he’s not near an ocean, therefore local measures cannot be measuring SEA LEVEL RISE.”

    No I did read that, though not with enough depth I’ll grant you. But regardless of all of those confounding additional factors, one would imagine that SLR should still impact at some point.

    “[R]egardless of all of those confounding additional factors”?!

    Really?

    Seriously?

    Surely there must be an actual physical impact from SLR. Various local factors can’t constantly mask those can they? If they do, then what concern should we express for a SLR that doesn’t actually DO anything?

    Sea level hasn’t been masked. In Australia, at Port Aurthur, mean sea level has risen 24 centimetres (almost 10 inches for the non-metric) since 1870. That’s a change that has been accomodated to date.

    However, science that is more reliable than your eyechrometer shows objectively that sea level rise is accelerating, and the future rise is a different story to that of the last century or so.

    You don’t spent all of your time looking over your shoulder when you drive. The same principle applies to sea level rise.

    SD makes a fair point regardless of the charges against him.

    No, he doesn’t. His point is specious, and wrong

    Where he is, SLR has had little appreciable impact.

    For the hard of learning – that would be a consequence of the fact that where Drongo’s wall is, is not the sea.

    And when can we expect SLR to overwhelm these local conditions? After all, it hasn’t happened for 70 years so far…

    It’s quite possible that sea level rise will not “overwhelm these local conditions” within your lifetime, except during storm conditions when they superimpose on surges. However the whole issue of sea level rise (and of global warming) is about considering future generations – although I realise that self-absorbed retirees all too frequently don’t give a rat’s arse about their grandkids, and especially about the grandkids of other people.

    Given the influx of Drongo’s friends, I’m guessing that Marohasy has gone quiet on her blog again. This sudden appearance of moral support for a scientifically-bankrupt claim occurred last time the Swamp dried out.

    [*Ironic pointing out of context...]

  86. #86 Bernard J.
    December 29, 2012

    Still on the distractions huh? Still, I’m happy to play your game.

    BJ, you hand-waving simpleton, you still don’t choose to understand that an upturned multihull is the result of positive feedback. An unrecoverable situation that the world’s climate has never entered whereas a self righting system is what we have or we wouldn’t be here.

    1. Tipping over a multihull usually has nothing to do with a positive feedback. Take the simplest case of a strong gust. It’s the equivalent of a climate forcing, and it can shift the position of the multihull to a new equilibrium with no change in feeding back from other ‘forcings’. You are wrong.

    2. There are positive feedings-back involved in global warming. So once again you are wrong.

    3. Feedings-back can have gains greater than or less than 1, and further these gains may be variable over the range of the independent variable(s). The evidence suggests that warming feedings-back have a gain less than 1.

    Now even you may have noticed while sipping absinthe on your balcony that the Gold Coast is essentially a flood plain. The Nerang estuary has the same tide range as the Broadwater and with the Seaway construction it also got lower low tides and higher high tides however the highest high tides are still lower than they were ~50 years ago.

    If you stopped in your persistence of ignoring all of the confounders that have been pointed out to you, you’d realise why your claim about a high king tide decades ago is specious.

    Are you seriously inferring that dam construction would reduce these estuary and SLs?

    As well as dredging entrances?

    I note that you answered my question with a question (or two). However I will answer yours because I am not afraid of the answer.

    Yes, damming a river upstream will affect the tidal height it achieves in its lower reaches. Whilst any river is affected by impounding effects (that is, whilst it is not wholely hydrodynamically contiguous with the open ocean) it’s own flow superimposes on oceanic tidal inflow.

    Crack open a text for once and learn. Or speak to a hydrologist and learn from practical knowledge, instead of inventing grandpa theories yourself that aren’t based in reality.

    ..this is just ONE of many benchmarks on SLs that I have accrued over ~70 years and they all agree. For example, the house I lived in at Cleveland Point in 1946 where the highest tides covered the lawn and threatened to run into the well we had just dug that was our only water supply, forcing us to quickly put a levy bank around it. The highest tides today are ~ 30 cms lower yet the landscaping is still the same and the well is still there.

    So, the local ocean hydrodynamics are the same? The meteorological factors (especially the barometric pressures) are the same, and coincident with the tides? The Bay’s engineering and hydrodynamics remain the same? For that matter, what’s your proof that the “landscaping is still the same”? How do you know that there hasn’t been build up of soil/sand/other substance, whether deliberate of by erosion from elsewhere?

    As ever, you are evidence-free, and context free.

    I also have many friends who have spent their lives by the sea in sea-front houses and sea-front businesses with sea-front infrastructure, who naturally pay great attention to the world’s concern with climate change and SLR and who are aware of what it entails for them much more than the average person and while many of them don’t measure the high tides to the last millimetre, they invariably tell me that the highest tides are no higher than they ever were in their experience.

    Well, that’s a how-do-you-do. I too have friends, acquaintances, and clients who have historical knowledge of tides, and in my corner of the world some have recently experienced tidal surges that they’ve never experienced before. I’m sure that there are one or two other locations* around the planet where similar situations have occurred.

    By your logic that proves that sea levels are rising…

    For the record, I have as little regard for positive anecdotes as I do for negative ones, unless they are supported by accurate and objective data. The presence of such data is something that has never cluttered your posts.

    But let’s go back to the beginning.

    Are you claiming that this is a fabricated phenomenon:

    http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html

    A simple “yes” or “no” will suffice for starters.

    [*Sarcasm, for the old autistics here]

  87. #87 Bolt for PM
    December 29, 2012

    Bernard, the first of your two responses above do little more than agree with what I am raising. You have pointed out firstly that SLR at Port Arthur has risen 10″ since 1870, which is around what, 1.7 mm/yr. Regardless of the rate, that is hardly dangerous and appears to have been well managed.

    You then go on to note that appreciable impacts may not be noted in our lifetimes, this is all about the kids. OK… But all you’ve done is show that SLR is still relatively steady. Sure there was (according to the graphs) some small acceleration in the early 20th C, but not so much since. Yet we are at a time of quickly rising CO2. So, no sign of anything as yet.

    Nonetheless, are there any real world effects? Well, no seems to be the consensus. Not yet.

    SD’s place of observation is in a river close to its mouth, yet you argue strenuously that SLR is unlikely to affect it. Maybe that’s so. But wouldn’t you agree that one day it will? Your very next sentence appears to suggest that. So, we are back to this ‘future’ impact for which records to date do not support?

    In summary then.

    SLR has been relatively steady since about 1930.
    It did accelerate in the early part of the 20th Century.
    Recent numbers do not show a significant change in that rate of rise.
    No-one here can point to a real world effect of any magnitude. So far.

    In your second post, after a bit more waffle, you throw up a nice graph which I’ll admit does show something actually happening in the past few years but which itself argues for a steady rate of rise overall. So where’s this acceleration that the actual main post is arguing for? As that graph says “This is more than 50% larger than the average value over the 20th century. Whether or not this represent a further increase in the rate of sea level rise is not yet certain.” How would that number of 3.2mm compare to the average value over the period from say 1940 to 1990? What is the average from the data for the period 1940 to 2012? After all, the really big increase in CO2 and presumably the effects of this occurred after 1940.

  88. #88 David B. Benson
    December 29, 2012

    One could try to put a tide gauge where there is a
    http://en.wikipedia.org/wiki/Tidal_bore
    but I suspect it would not work well.

  89. #89 David B. Benson
    December 29, 2012

    Bolt for PM — The warming effect of atmospheric CO2 is logarithmic in the concentration relative to some chosen starting concentration. So the effect is (quite) approximately linear since about 1750 CE.

    Your time intervals are much too short to be of climatological interest.

  90. #90 Lotharsson
    December 29, 2012

    Lothe, If you haven’t the faintest idea, and you haven’t, dont comment.

    That’s precisely why I comment, my dear. I only do it when I have a lot more than the faintest idea, or I’m asking questions of those who claim to. Like your good self.

    Shame you don’t follow your own advice though.

    So we see that you refuse to define your terms. And you won’t answer questions that are simple to answer if you understand those terms. The sum total of what you have to date appears to be bluster and misconception – and you’re grimly hanging on to both.

    Here’s half a clue.

    1) A system may have more than one feedback operating at the same time. In particular a positive feedback may be operating at the same time as a negative one.

    2) What matters when figuring out how the system will behave in the short term is the nett feedback – the sum of all feedbacks, both positive and negative.

    3) The set of feedbacks – and their various strengths – that affect a system may change over time, depending on what state the system is in. Some feedbacks may even cease to operate outside of certain parameters. Just to make it clear, that means the nett feedback may vary from positive to negative or vice versa, and from strong to weak or vice versa, over time.

    4) A NETT positive feedback may affect a system at all times and under all states without causing the system to “run away”. (This is precisely why I asked – and you refused – to answer the question about a positive feedback with a 50% gain.) This is part of Feedback 101. It’s a fundamental principle that forms the basis of signal amplifiers that use positive feedback.

    5) Because of (2)-(4) you can’t infer that there are no positive feedbacks from observation that a runaway situation has not occurred. Heck, (3) alone breaks your claim, as does (4) alone.

    6) “Self-righting” in boats is not THE SAME AS negative feedback, and the existence under normal conditions of A negative feedback is not sufficient to create a “self righting” system. Self-righting is (roughly speaking) an example of what is known as a system with a “stable equilibrium” perturbed by a set of time-changing forces. Sure, there must be nett negative feedbacks at work in systems that exhibit stable equilibria, but merely having a negative feedback at work ISN’T SUFFICIENT. You need either (a) the nett feedback to be strong enough (gain <= -1) to overcome the change in input, or (b) with weaker nett feedback you need the change in input to be non-permanent so that once the change in input goes away the feedback can push the system back to equilibrium.

    In particular a positive feedback may operate at the same time as a negative one, and one can STILL have a stable equilibrium.

    7) Furthermore, many systems with stable equilibria have a limited range over which the system will revert to the equilibrium state. Push them (with a strong enough input change) outside of that range and they will go elsewhere, and without some other strong enough push back they will not revert to the equilibrium state. (I’m pretty sure if you carefully analyse a multi-hull – given that people use them without routinely needing to call for help to right them – you’ll find this is the case. They exhibit a stable equilibrium up to a certain point but after that the nett feedback becomes sufficiently strong to cause a tip over.)

    You can see that (4) and (5) and (7) are why I asked you about multi-hulls. You allege they tip over because of positive feedback – but presumably many of them never tip over at all. And yet you allege that there is (and apparently cannot be) any positive feedback in the climate system because it hasn’t run away yet. Even if you won’t admit the fallacy – either about boat observations or about climate – I’m sure practically everyone else who’s read this far sees it.

    The long term existence (up to and including today) of some positive feedbacks are well established. They are what enabled life as we know it to evolve – the earth would be too cold otherwise. But if we perturb the climate enough, additional positive feedbacks will come into play (some of which are being observed as we speak) and existing ones will be strengthened, and it’s not at all clear that additional negative feedbacks/negative feedback strength will offset them. This will increase the nett positive feedback, which increases the effective amplification factor for any and all forcings on the system and causes it to warm even more than it would without the strengthened feedback (just like turning up the gain a bit on a positive-feedback amplification circuit, but not enough to generate a feedback screech which is a “runaway” effect).

    When climate scientists talk about positive feedbacks operating or new ones coming into play, they aren’t – no matter how many times you imply it – saying that a runaway situation must occur as a result (unless they’re specifically talking about pushing the climate to extreme conditions, which doesn’t get discussed very much). So your point that we haven’t had runaway warming in the past DOES NOT IMPLY that they are wrong about the various positive (and negative) feedbacks at work in the past, now and in the future.

    And I predict you will dismiss all of this ;-)

  91. #91 Bolt for PM
    December 29, 2012

    David Benson, you say:
    “Bolt for PM — The warming effect of atmospheric CO2 is logarithmic in the concentration relative to some chosen starting concentration. So the effect is (quite) approximately linear since about 1750 CE.

    Your time intervals are much too short to be of climatological interest.”

    Doesn’t that just confirm what I am saying? That firstly, the claims of the main post are wrong and that SLR is NOT accelerating? And secondly if responses are linear, then in effect little is different today than 100 years ago. And presumably, 100 years into the future?

  92. #92 Lotharsson
    December 29, 2012

    Sure there was (according to the graphs) some small acceleration in the early 20th C, but not so much since.

    Not quite. Several recent 20-yr trend rates have been the highest set on record (Fig 4 here), and (very roughly – eyeball estimate only) about 1mm per year higher than the average of 20-year trends centered on 1940-1990, as you were asking. As that article points out (including some of the comments) you probably want to account for some other factors at play too.

    And secondly if responses are linear, then in effect little is different today than 100 years ago.

    Well, apart from (a) rising annually at 2-3 times the rate 100 years ago, and (b) other clear signs that other factors that affect sea level rise are having larger and larger effects, some of which are expected to be decidedly non-linear, and others that will continue to do so for a long time. (Some effects operate over fairly long time intervals. The fact that their impacts due to past CO2 rises have not fully eventuated yet does not mean that those remaining impacts will not occur in future – along with the impacts of future CO2 emissions.)

    In summary, the fact that sea level rise has only doubled or tripled from a century ago thus far does not mean that it won’t get a lot faster still.

    So:

    And presumably, 100 years into the future?

    That’s an extremely unlikely outcome.

  93. #93 Bernard J.
    December 29, 2012

    You then go on to note that appreciable impacts may not be noted in our lifetimes, this is all about the kids. OK… But all you’ve done is show that SLR is still relatively steady.

    Blot for PM.

    You misrepresent my comments.

    A rise of around 2 mm to 3 mm per year is not going to have an appreciable impact on coast structures in the short term and outside of extreme weather event. In this sense you and Drongo aren’t saying anything that all scientists don’t themselves recognise.

    This however does not preclude the fact that even centimetres of sea level rise have appreciable impacts during extreme weather events, that the near future will see such events, and that smarter people than you are preparing for it – my countrymen in the Netherlands for starters…

    Sure there was (according to the graphs) some small acceleration in the early 20th C, but not so much since.

    There doesn’t need to be a large acceleration in the current rate of sea level rise for serious destruction of much coastal infrastructure within a century or so, as that rate is already above the Holocene mean.. That said, there is no science that can explain why there won’t be acceleration in the future (and the OP shows that this is the case) – but by all means please point us to any of which you are aware.

    Yet we are at a time of quickly rising CO2. So, no sign of anything as yet.

    You are engaing in the gambit of confabulating signal with noise, especially by cherry-picking short intervals of time.

    That’s either unconscious or deliberate ignorance.

    SD’s place of observation is in a river close to its mouth, yet you argue strenuously that SLR is unlikely to affect it. Maybe that’s so. But wouldn’t you agree that one day it will? Your very next sentence appears to suggest that. So, we are back to this ‘future’ impact for which records to date do not support?

    Eh? You think that past changes to the Nerang watershed should support indications of “‘future’ impact”?

    You’re off your rocker.

    SLR has been relatively steady since about 1930.

    Not compared to the mean Holocene rate of change, it hasn’t.

    It did accelerate in the early part of the 20th Century.

    Again, the acceleration emphasis, without acknowledging that there’s already a significant positive rate of increase.

    Recent numbers do not show a significant change in that rate of rise.

    A rate which is already significant…

    And compared to a century ago, the rate has significantly increased.

    In your second post, after a bit more waffle, you throw up a nice graph which I’ll admit does show something actually happening in the past few years but which itself argues for a steady rate of rise overall.

    What you are doing here is implicitly regressing beyond the independent variable range. This is one of the basic mistakes of employing regression. A regression is not a physically-based model, and so should not be used for extrapolations or predictions – especially as oceanographers recognise that the physical processes involved are in dynamic flux.

    And surprise,surprise, the longer-term graph of sea level rise (that first graph in the OP) shows that there is indeed something happening that is not identified in short-term graphs.

    So where’s this acceleration that the actual main post is arguing for?

    Calculate a second differential for the first graph. That’s the whole bloody point.

    As that graph says “This is more than 50% larger than the average value over the 20th century. Whether or not this represent a further increase in the rate of sea level rise is not yet certain.” How would that number of 3.2mm compare to the average value over the period from say 1940 to 1990? What is the average from the data for the period 1940 to 2012? After all, the really big increase in CO2 and presumably the effects of this occurred after 1940.

    You’re the one saying that there’s no acceleration, so you should be the one answering all of your questions. Or are you making claims about “acceleration” without having actually done any work to support them?

    On the matter of the relationship with atmospheric CO2 concentration, you seem to be ignoring the small matter of huge thermal mass/inertia…

  94. #94 Bernard J.
    December 29, 2012

    You then go on to note that appreciable impacts may not be noted in our lifetimes, this is all about the kids. OK… But all you’ve done is show that SLR is still relatively steady.

    Blot for PM.

    You misrepresent my comments.

    A rise of around 2 mm to 3 mm per year is not going to have an appreciable impact on coast structures in the short term and outside of extreme weather event. In this sense you and Drongo aren’t saying anything that all scientists don’t themselves recognise.

    This however does not preclude the fact that even centimetres of sea level rise have appreciable impacts during extreme weather events, that the near future will see such events, and that smarter people than you are preparing for it – my countrymen in the Netherlands for starters…

    Sure there was (according to the graphs) some small acceleration in the early 20th C, but not so much since.

    There doesn’t need to be a large acceleration in the current rate of sea level rise for serious destruction of much coastal infrastructure within a century or so, as that rate is already above the Holocene mean.. That said, there is no science that can explain why there won’t be acceleration in the future (and the OP shows that this is the case) – but by all means please point us to any of which you are aware.

    Yet we are at a time of quickly rising CO2. So, no sign of anything as yet.

    You are engaing in the gambit of confabulating signal with noise, especially by cherry-picking short intervals of time.

    That’s either unconscious or deliberate ignorance.

    SD’s place of observation is in a river close to its mouth, yet you argue strenuously that SLR is unlikely to affect it. Maybe that’s so. But wouldn’t you agree that one day it will? Your very next sentence appears to suggest that. So, we are back to this ‘future’ impact for which records to date do not support?

    Eh? You think that past changes to the Nerang watershed should support indications of “‘future’ impact”?

    You’re off your rocker.

    SLR has been relatively steady since about 1930.

    Not compared to the mean Holocene rate of change, it hasn’t.

    It did accelerate in the early part of the 20th Century.

    Again, the acceleration emphasis, without acknowledging that there’s already a significant positive rate of increase.

    Recent numbers do not show a significant change in that rate of rise.

    A rate which is already significant…

    And compared to a century ago, the rate has significantly increased.

    In your second post, after a bit more waffle, you throw up a nice graph which I’ll admit does show something actually happening in the past few years but which itself argues for a steady rate of rise overall.

    What you are doing here is implicitly regressing beyond the independent variable range. This is one of the basic mistakes of employing regression. A regression is not a physically-based model, and so should not be used for extrapolations or predictions – especially as oceanographers recognise that the physical processes involved are in dynamic flux.

    And surprise,surprise, the longer-term graph of sea level rise (that first graph in the OP) shows that there is indeed something happening that is not identified in short-term graphs.

    So where’s this acceleration that the actual main post is arguing for?

    Calculate a second differential for the first graph. That’s the whole bloody point.

    As that graph says “This is more than 50% larger than the average value over the 20th century. Whether or not this represent a further increase in the rate of sea level rise is not yet certain.” How would that number of 3.2mm compare to the average value over the period from say 1940 to 1990? What is the average from the data for the period 1940 to 2012? After all, the really big increase in CO2 and presumably the effects of this occurred after 1940.

    You’re the one saying that there’s no acceleration, so you should be the one answering all of your questions. Or are you making claims about “acceleration” without having actually done any work to support them?

    On the matter of the relationship with atmospheric CO2 concentration, you seem to be ignoring the small matter of huge thermal mass/inertia…

  95. #95 David B. Benson
    December 29, 2012

    Bolt for PM — While thermal expansion of the ocean via heating is about linear in the temperature increase the melting of ice is highly nonlinear as the local temperature first peeks above the melting temperature of the water.

    After that I cannot easily state, but look at SLR from LGM to the Holocene; an S-shaped curve over 120–130 meters. I’ll predict a similar S-shaped curve this time around, but I doubt the eventual increase will be quite so large.

  96. #96 spangled drongo
    December 29, 2012

    “Tipping over a multihull usually has nothing to do with a positive feedback”

    Yeah, sure.

    When a multihull starts to incline beyond an angle where everything on board tends to fall to the low side and the wind gets under the wings, forces that will make it capsize increase and stability reduces. The centre of gravity moves even further outboard of the centre of buoyancy and positive feedback is happening. The multihull is now beyond saving and will overturn. This can happen at an inclination of as little as 45 degrees. Once overturned it will not self right. A properly ballasted monohull OTOH can be fully inverted to 180 degrees and will still self right. The more it inclines the more the forces to make it incline, generally, are reduced. Also the mast is more likely to break off than the keel. More negative feedback.

    “So, the local ocean hydrodynamics are the same?”

    BJ, are you now saying the same for Moreton Bay? That you can reduce SLs by dredging the Shipping Channel? Or the port of Brisbane?

    That is about as smart as the argument that local SLs can fall over ~70 years but world wide they can acceleratingly rise to alarming heights.

    “I too have friends, acquaintances, and clients who have historical knowledge of tides, and in my corner of the world some have recently experienced tidal surges that they’ve never experienced before.”

    In case you hadn’t noticed BJ, we aren’t talking about SURGES. Post tropical storm Sandy was a SURGE. Fukushima was a SURGE. Surges come from a one-off force, tides are regular. But if you have friends who have intelligent, long term observations of regular SLR from king tides, please supply details similar to mine; time, place, levels etc.

    Detailed anecdotes ARE data. And here’s me thinking I am dealing with a scientist.

    “But let’s go back to the beginning.”

    Bernie love, that link we have discussed ad nauseum in the past. Your beloved Church and White won’t even admit that the Ross-Lempriere mark shows a SL fall of around 30 cms but at least they agree that it shows a SLR of 13.5 cms over 171 years which is 0.8 mm/y which in effect shows that nothing much is happening.

    As I have said before, when SL is measured from an orbiting spacecraft that cannot fly parallel to our pear-shaped-geoid-with-flat-spots and the sea surface has possibly one hundred thousand different levels in any one day if you are using 0.1 mm increments, which they are, which are then fed into supercomputers with their usual assumptions and adjustments, to think that is empirical measurement you have to have rocks in your head. How many times have they decided to “adjust’ GRACE and she is supposed to be much more accurate. Envisat showed no SLR until made to toe the line.

    I’d rather believe detailed obs any day.

    How are you going with your PhD?

  97. #97 spangled drongo
    December 29, 2012

    Things may not be as bad as we thought. More dances with GRACE:

    http://www.theregister.co.uk/2012/11/28/sea_levels_new_science_climate_change/

  98. #98 chameleon
    December 29, 2012

    Loved your link David B and also like the way you comment.
    You actually deal with the message.
    So even though we may disagree, good for you.

  99. #99 Lotharsson
    December 29, 2012

    Things may not be as bad as we thought.

    So now you agree with GRACE (but only as interpreted by (well-known for pushing denialist talking points) The Register?!)

    Here’s another report indicating that the paper your article talks about doesn’t change the current understanding very much.

    Here’s another.

    Measurements show the rate of melting is accelerating by 9 billion tons each year, Harig said. The study doesn’t include measurements from 2012, when a record-breaking amount of ice melted in Greenland.

    “I would fully expect when I get that data, it’d show ice loss accelerating even more,” he said. “Records keep being broken.”

    Here’s another one saying much the same.

    And that journal article doesn’t cover the last couple of years of record Greenland melt.

    Your article’s interpretation appears to be inaccurate.

  100. #100 spangled drongo
    December 29, 2012

    “In the latest work, Princeton University researcher Chris Harig and Frederik Simons applied a new method to analyzing the GRACE data”

    It seems that when you are dancing with GRACE you can choose your own tune.

    That’s really the point I am trying to make.

    How can you call this stuff data?

    And Lotharsson, I wonder if that 13,000 years includes the refreezing that’s happening with a vengeance right now?

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