Hansen's Kingsnorth Testimony

A reader writes in about Hansen’s submission at the Kingsnorth trial. I’m posting up a thread under a couple of conditions. Hansen’s take on scientific matters is influential and important and discussion of scientific topics will be permitted. Please do not post on anything that remotely touches on policy. Please do not make posts complaining or whining about Hansen or AGW or alarmism or anything like that. I’m not going to bother snipping, I’m just going to delete posts that don’t comply. Using words like Cenozoic in the post is encouraged.

Is Steve or anyone interested in taking a look at Hansen’s written submission in the Kingsnorth trial?

It’s online here:

http://www.greenpeace.org.uk/files/pdfs/climate/hansen.pdf

Excerpts from his Q & A are here:

http://www.greenpeace.org.uk/blog/climate/kingsnorth-day-three-trial-jim-hansen-20080903

Written statements from the other defence witnesses are here:

http://www.greenpeace.org.uk/blog/climate/kingsnorth-trial-witness-statements-full-20080912


239 Comments

  1. jeez
    Posted Sep 16, 2008 at 7:14 PM | Permalink | Reply

    Moshpit just stepped on my Cenozoic and it’s swelling rapidly.

  2. ep
    Posted Sep 16, 2008 at 7:45 PM | Permalink | Reply

    I’d love to comment, but as I live only a few miles away from Kingsnorth I am having to type these messages with intermittent power cuts. So please excuse my

  3. Gerald Machnee
    Posted Sep 16, 2008 at 7:58 PM | Permalink | Reply

    Did they have any real scientists give evidence? Or was it all one side?

  4. Craig Loehle
    Posted Sep 16, 2008 at 8:24 PM | Permalink | Reply

    Being in Forestry I noted that Hansen suggests we burn trees instead of fossil fuels. That would be fine except we are already cutting trees to make paper and lumber, and people don’t even like that much cutting. Mmmm…

  5. MarkR
    Posted Sep 16, 2008 at 8:32 PM | Permalink | Reply

    Hansen says:

    Close examination of glacial-interglacial data reveals that temperature change usually leads the GHG change. This is as expected, because the GHG change is a feedback to the temperature change. The average lag is a few hundred years, the time required for CO2, which is the dominant GHG feedback, to be flushed from surface reservoirs, mainly from the ocean.

    I’m confused. Is Hansen saying CO2 is a feedback or a forcing, or both?

    But at least I have learnt that:

    …during the period 60 My BP (60 million years before present)to 50 My BP India was plowing north rapidly (20 cm per year) through the Tethys Ocean and in the process…

    ….zzzzzzzzz

    • bender
      Posted Sep 16, 2008 at 9:16 PM | Permalink | Reply

      Re: MarkR (#5),
      Both. And that is the best verbal explanation I’ve read to date how CO2 can play both roles simultaneously, leading to a schizoid lead-lag pattern. It leads in cause, it lags in response (because of the oceans). I’m quite weary of “skeptical” arguments that fail to understand how this can happen in a lagged positive feedback system.

      • Ernie
        Posted Sep 16, 2008 at 9:29 PM | Permalink | Reply

        Re: bender (#7), I don’t get it, if the CO2 leads and lags temperature why doesn’t that lagging rise in CO2 act as leading increase forcing an even greater release -> lagging CO2 rise until the ocean has released all it can? ie. a runaway forcing event.

        – Ernie.

        • bender
          Posted Sep 16, 2008 at 9:40 PM | Permalink

          Re: Ernie (#9),
          Similar to Will: Are you assuming here that other forcing agents don’t cap runaway feedback behavior?

        • Ernie
          Posted Sep 16, 2008 at 9:45 PM | Permalink

          Re: bender (#11), Not assuming a thing, just want to know why it doesn’t run away out of control, “Tipping Point” I believe its called.

          If there is some negative feed back that prevents it running away this is a good thing isn’t it?

          – Ernie.

  6. Ernie
    Posted Sep 16, 2008 at 9:06 PM | Permalink | Reply

    snip -policy

  7. Posted Sep 16, 2008 at 9:25 PM | Permalink | Reply

    Excuse my ignorance, but if CO2 is an amplifier or driver then on the other side of the cycle, wouldn’t CO2 then have to drop before temperatures followed? If so, does the data show this?

    • bender
      Posted Sep 16, 2008 at 9:32 PM | Permalink | Reply

      Re: Will Nitschke (#8), That would be true only if CO2 were the only forcing agent. It is not. There are other forcing agents that are not involved in feedbacks.

  8. Posted Sep 16, 2008 at 9:44 PM | Permalink | Reply

    OK, sorry for the additional question: how does one then separate agents that are ‘significant’ contributors to warming from agents that just happen to be ‘going along for the ride’ so to speak? Co-related but not causal. This seems to be a common problem in medical trials, but I’m under the impression that there are certain statistical techniques that can be used to shed (some) light on such issues. Can this be done in the climate sciences? My concern is that hypothesises may be (realistically) untestable and degenerate to ‘just so’ stories. Is there a link to a detailed technical discussion of this issue available anywhere I could read up on? Does Hansen discuss his statement in the published literature in more detail anywhere I could find?

  9. John A
    Posted Sep 16, 2008 at 9:50 PM | Permalink | Reply

    Both. And that is the best verbal explanation I’ve read to date how CO2 can play both roles simultaneously, leading to a schizoid lead-lag pattern. It leads in cause, it lags in response (because of the oceans). I’m quite weary of “skeptical” arguments that fail to understand how this can happen in a lagged positive feedback system.

    I’m quite weary as to how cause can follow effect by centuries. So perhaps you could explain in short scientific steps how this can happen rather than patronize everybody with a non sequitur argument.

    • bender
      Posted Sep 16, 2008 at 9:56 PM | Permalink | Reply

      Re: John A (#14),
      oceans

      • John A
        Posted Sep 17, 2008 at 12:06 AM | Permalink | Reply

        Re: bender (#16),

        oceans

        Not an answer to the question. The question is: how does a rise in carbon dioxide cause a rise in temperature eight hundred years previously?

  10. Andy
    Posted Sep 16, 2008 at 9:50 PM | Permalink | Reply

    At least Hansen didn’t make any statement about the climate of last millenium, and the HS wasn’t there!

  11. bender
    Posted Sep 16, 2008 at 10:01 PM | Permalink | Reply

    More precisely:

    Warming begins promptly, but it takes a few decades for the ocean surface temperature to achieve just half of its ultimate (‘equilibrium’) response, and a few centuries for full response.

    This answers your very good question:

    how cause can follow effect by centuries

    • Raven
      Posted Sep 16, 2008 at 10:16 PM | Permalink | Reply

      Re: bender (#17)
      Of course, that argument implies that we cannot draw any conclusions about what has caused the recent warming if we don’t know what was happening to the oceans 1000 years ago…

      • bender
        Posted Sep 17, 2008 at 7:43 AM | Permalink | Reply

        Re: Raven (#20),
        Yes, I’m aware of that. But I don’t suggest discussing it here, as the focus should be on the Hansen document. (That’s why my reply to John A was short.)

        The thing that struck me about the Hansen testimony is his certainty on the “tipping point”. What was it – 450ppm CO2? Was this number calculated somehow? Deduced from model behavior? How did he get it? Deducing tipping points from model output is not an easy thing to do. To be so certain requires analytical math of very small systems of equations. Yet this is not what Hansen does. Frankly, I was stunned that he was so forthright with an exact number.

        • DeWitt Payne
          Posted Sep 17, 2008 at 8:20 AM | Permalink

          Re: bender (#58),

          There must be a source of the 450 ppm number. Leif Svalgaard used the same number in Svalgaard #7 or #8. I’ll try to find it.

          It was on the Ice Ages thread here and it was ~500 not 450, but close enough. There is a linked paper in the post. But let’s not reinvent the wheel here. The topic was discussed at length on the Ice Ages thread.

        • bender
          Posted Sep 17, 2008 at 8:47 AM | Permalink

          Re: DeWitt Payne (#63),
          He cites two papers in arxiv.

    • John A
      Posted Sep 17, 2008 at 12:09 AM | Permalink | Reply

      Re: bender (#17),

      Warming begins promptly, but it takes a few decades for the ocean surface temperature to achieve just half of its ultimate (‘equilibrium’) response, and a few centuries for full response.

      So how does the warming happen in the first place? How does the ocean know to warm for a future carbon dioxide rise?

  12. Ian McLeod
    Posted Sep 16, 2008 at 10:09 PM | Permalink | Reply

    The first eight pages were interesting, reasoned, and for the most part scientific. Then, facts slowly begin transposing into opinion, teleconnecting back to Al Gore’s movie. Gore can now say confidently, “I told you my movie was based on sound science,” and why not, based on what Hansen has written.

    I counted eight suppositions which Hansen turned into undeniable facts, like the IPCC Policy Statements. In one respect, Hansen’s paper saddens me. We have lost a good scientist, a critical thinker, to crack pottery.

    It reminds me of an anecdote from Sir Winston Churchill’s biography, Churchill and America, by Martin Gilbert (2005). A loud and boisterous women from across the floor, furious with Churchill’s economic acumen, shouted out, “If I was your wife, I’d poison your coffee.” To which Churchill replied, “If I was your husband madam, I’d drink it.”

    When a world renown scientist can chortle out rubbish with such a poisoned pen, one is helpless to consider Churchill’s quip.

  13. Steve McIntyre
    Posted Sep 16, 2008 at 10:10 PM | Permalink | Reply

    Please move on from Co2 lead-lag discussions, which I’m weary of. TRy tofind something new in this paper to discuss or else there’s little point in having this thread.

  14. kuhnkat
    Posted Sep 16, 2008 at 10:16 PM | Permalink | Reply

    Bender,

    since the air warms with the ocean surface, doesn’t the real work occur subsurface where the suns energy is absorbed 10’s of meters deep (or is that what you MEAN when you refer to the surface??)

    Shouldn’t we still be seeing a warming, or at lease stable, ocean IF there really is this fairy tale AGW??

    Why doesn’t the Argo data, or any other data, indicate even a stable ocean temp??

    IF there is WARMING IN THE PIPELINE, as you assume, WHERE IS IT, hiding in molecules in an unknown quantum state????

  15. Posted Sep 16, 2008 at 11:15 PM | Permalink | Reply

    Hansen:

    The claim that “we cannot predict next month’s weather in London, so how in the world can we predict the effect of human-made greenhouse gases in 50 years!” is a nonsensical statement, failing to recognize the difference between chaotic weather fluctuations and the deterministic response of the Earth to a large change in the planet’s energy balance.

    Koutsoyiannis:

    * However, model outputs at annual and climatic (30?year) scales are irrelevant with reality; also, they do not reproduce the natural overyear fluctuation and, generally, underestimate the variance and the Hurst coefficient of the observed series; none of the models proves to be systematically better than the others.

    * The huge negative values of coefficients of efficiency at those scales show that model predictions are much poorer that an elementary prediction based on the time average.

    * This makes future climate projections not credible.

    http://www.itia.ntua.gr/en/docinfo/850

    Who is credible here, Koutsoyiannis or Hansen? IF Koutsoyiannis is not credible and Hansen is correct, on what basis please?

  16. Brian Johnson
    Posted Sep 16, 2008 at 11:16 PM | Permalink | Reply

    Hansen -snip-snip-snip-snip-tipping point -snip -snip -snip – sea level rise – gulp – snip – snip -snip – Al Gore -SNIP – Kingsnorth – cold – snap – snip……..

  17. Julian Flood
    Posted Sep 16, 2008 at 11:40 PM | Permalink | Reply

    I have changed computers so I have lost the reference: does anyone remember the recent paper which asserted that GW is caused by ocean warming and this is _followed_ by land warming? Earlier this year, I think. I can’t find it on Google.

    JF

  18. anna v
    Posted Sep 16, 2008 at 11:47 PM | Permalink | Reply

    A crux is here:

    The claim that “we cannot predict next
    month’s weather in London, so how in the world can we predict the effect
    of human-made greenhouse gases in 50 years!” is a nonsensical
    statement, failing to recognize the difference between chaotic weather
    fluctuations and the deterministic response of the Earth to a large change
    in the planet’s energy balance.

    It is an assumption of enormous hubris to say that there is a deterministic response to a large change in the planet’s energy balance.

    It is easy to wave chaos around, and then say you contain it deterministically , but the proof is in the pudding.The Koutsoyannis papers show experimentally that there is nothing deterministic in climate models that have such a premise.

    The tiny interference of CO2 is in no way a large change in the planet’s energy balance if computer model feedback mechanisms are not introduced.

    Close examination of glacial-interglacial data reveals that temperature
    change usually leads the GHG change. This is as expected, because the
    GHG change is a feedback to the temperature change. The average lag is
    a few hundred years, the time required for CO2, which is the dominant
    GHG feedback, to be flushed from surface reservoirs, mainly from the
    ocean4.

    Even if this lagged or what not CO2 feedback argument is right ( it is too much for my poor little physicist brain, I would need an electronic prototype) we must still have a few hundred years from 1950s when we sinned and burned and produced CO2, until we see this glorious lagged or what not feedback operating. The oceans are still big enough.Why do I have the impression AGW people say we have no time and have to act right now? Are the CO2s coming from people weighted up by factors of hundreds?

    Even one hundred years will be enough for fusion to come on line and most of the energy will come without CO2 tags, so what is the rush?

    Natural climate changes on millennial time scales are instigated by Earth
    orbital changes, but the mechanisms causing planetary energy imbalance
    and global temperature change are the ice-albedo and GHG feedbacks.
    Both mechanisms are now under control of humans: GHGs have increased
    far above levels that existed during the past few million years and ice
    sheets are disintegrating in both hemispheres. Humans will determine
    future climate change.

    Here it is in black and white, and if this is not collective delusion of grandeur, I do not know what is. Hubris for sure.

    Oh dear:

    But shouldn’t Earth now, or at some point, be headed into the next ice
    age? No. Another ice age will not occur, unless humans go extinct.
    Orbital conditions now are, indeed, conducive (albeit weakly6) to initiation
    of ice sheet growth in the Northern Hemisphere But only a small amount
    of human-made GHGs are needed to overwhelm any natural tendency
    toward cooling. The long lifetime of human-made CO2 perturbations
    assures that no human generation that we can imagine will need to be
    concerned about global cooling. Even after fossil fuel use ceases and its
    effect is drained from the system an ice age could be averted by
    chlorofluorocarbons (CFCs) produced in a single CFC factory. It is a trivial
    task for humanity to avert an ice age.

    I do not want to comment on the man who believes this, as it seems he does. I had had some trouble finding a link to such statements by Hansen because people would not believe me.

    King Kanute for sure.

  19. pft
    Posted Sep 16, 2008 at 11:56 PM | Permalink | Reply

    So he goes back 60 million years to the Cenzoic era to explain the warming and subsequent cooling. Yet he chooses not to explain the last ice age and warming that has given us the present interglacial of the last 12,000 years, let alone the MWP and Little Ice Age.

    He also mentioned ice began forming at the poles at about 450 ppm CO2. But his own paper that is linked admits that uncertainties of CO2 in this period at these levels is +/- 400 ppm.

    Also, this article touches on how uncertain a lot of what we think we know of the past is.

    http://www.sciencedaily.com/releases/2008/09/080910104202.htm

    He mentions at one point that increased CO2 from natural sources results in a temporary (not quantified) absorption of heat in the lower troposphere before thermal equilibrium is restored as the CO2 is released into space from higher and cooler parts of the atmosphere. But in talking about mans CO2 causing a potential doubling, the word temporary disappears.

    If you look in the deserts and notice the tremendous difference between night time and daylight temperatures, it is clear CO2 is not very efficient on it’s own at capturing that heat and keeping the surface warm.

  20. Nylo
    Posted Sep 17, 2008 at 12:04 AM | Permalink | Reply

    As the oceans get hotter, and without other important CO2 sources to the atmosphere, they will release CO2. That’s the lagging we see in historical records. This is compatible with CO2 being a forcing of its own. There are 2 reasons for this not being a runaway process. First, that the more CO2 you have in the atmosphere, the lesser effect any further addition will have. Second, whichever forcing caused the temperatures to start rising in the first place, can disappear, leaving a planet hot enough to cool in spite of the increased GH effect. And as it cools, the oceans absorb CO2 which causes further cooling, etc.

    The situation now is different. We have a massive source of CO2 to the atmosphere, other than the oceans. In the past, when other forcings disappeared and only a big ammount of GHGs were left, the planet was hotter than equilibrium, and because of that it cooled. However, now, assuming no other important forcings are in play, the planet temperatures are under equilibrium, because the GHGs didn’t have enough time yet to warm us, it is a slow process, and because of that the planet temperatures will tend to rise.

    This is of course a lot of especulation, especially the part that assumes that there is such a thing as a planetary temperature equilibrium and the part that assumes that we are not suffering any other important forcings. But considering those assumptions, it is clear that the planet would warm.

    It is less clear HOW MUCH it would warm, though. Because no matter what the IPCC tells, nobody has been able to prove what the climate sensitivity to CO2 in the atmosphere is. We only have the simulations of the models which are wildly imperfect. And IPCC talks to us about the average of the average of the models, trying to make it look like all the models agree. The truth is that different models and different runs of the models say such different things that it would be nuts to trust any of them. We will warm, yes, most probably, unless other forcings come into play, but any prediction as to how much, is pure especulation.

    We really only have our own experience. We can look back at the 20th century and ask some questions:
    1) How difficult has it been to deal with the rise in temperatures?
    2) How important has that temperature rise been compared with the other major historical events in the 20th century? Meaning, if we could take a time machine and travel to 1900 DC now, would we focus on stopping the industrial revolution, or would we try not to have a Hitler or a Stalin in the world?
    3) Therefore, has the global warming ever really been the biggest of our problems?

    • John A
      Posted Sep 17, 2008 at 12:11 AM | Permalink | Reply

      Re: Nylo (#27),

      As the oceans get hotter, and without other important CO2 sources to the atmosphere, they will release CO2. That’s the lagging we see in historical records. This is compatible with CO2 being a forcing of its own.

      This is preposterous. How can CO2 be a forcing of something that happened centuries ago?

      • Nylo
        Posted Sep 17, 2008 at 12:31 AM | Permalink | Reply

        Re: John A (#30),

        This is preposterous. How can CO2 be a forcing of something that happened centuries ago?

        It can’t. CO2 wasn’t the forcing which caused the initial temperature rise. There were other forcings in play, some major league players you may say. As the CO2 rised, it contributed to the warming. However it is imposible to say how much. Then when the major league players disappeared, CO2 slowed the cooling, but again, it is imposible to say to what extent. Historical records don’t give us a clue about that.

        • Posted Sep 17, 2008 at 12:43 AM | Permalink

          Re: Nylo (#32),

          John A.

          As the CO2 rised, it contributed to the warming. However it is imposible to say how much. Then when the major league players disappeared, CO2 slowed the cooling, but again, it is imposible to say to what extent. Historical records don’t give us a clue about that.

          Hansen (my emphasis):

          The fact that GHGs act as both climate forcings, which lead climate
          change, and climate feedbacks, which lag climate change, has been used by ‘contrarians’ to sow confusion about global warming. In reality, the leads and lags of GHGs and temperature have occurred just as expected. Indeed, empirical information on GHGs and climate change during Earth’s history provides powerful confirmation of our understanding of climate change as well as quantitative evaluation of the level of GHGs that will constitute dangerous interference with nature.

          Your statements possibly contracts those of Hansen, who states that “empirical information on GHGs…occurred just as expected.” I read this as asserting that the process is well understood and empirically established. I am wondering, what research does Hansen refer to here? He provides several citations in his presentation but not for the above assertion, unfortunately. Does anyone know? I would like to read up further on this if possible.

        • Nylo
          Posted Sep 17, 2008 at 1:03 AM | Permalink

          Re: Will Nitschke (#34),

          The emphasized part of Hansen statement is just false. We cannot know what the contribution of GHGs to the warmings was because we cannot know how strong the warming would have been with it. Historical records tell what happened, but don’t answer any what-ifs. It is true that historical records are COMPATIBLE with CO2 being a forcing (weaker than the others in play), but it is also true that historical records are COMPATIBLE with CO2 NOT being a forcing. So, in the end, they just don’t discard anything and don’t prove anything. You cannot claim evidence from them.

        • Posted Sep 17, 2008 at 2:12 AM | Permalink

          Re: Nylo (#32),

          It can’t. CO2 wasn’t the forcing which caused the initial temperature rise. There were other forcings in play, some major league players you may say. As the CO2 rised, it contributed to the warming. However it is imposible to say how much. Then when the major league players disappeared, CO2 slowed the cooling, but again, it is imposible to say to what extent. Historical records don’t give us a clue about that.

          No, none of that makes sense. The CO2 only began to rise after many centuries of warming, so couldn’t contribute to the warming.

          There is no evidence that “major league players” disappeared, otherwise we’d see this in the ice core record.

          Also the CO2 did not slow the cooling, because the temps fell just as quickly while CO2 continued to rise as it did when CO2 began to fall.

          You have cause and effect backwards.

          Re: Phil (#37),

          Thus, the hypothesis is its own initial premise, much as increased CO2 is both a cause and and effect of global warming. Positive feedback.

          I think you mean “circular reasoning”. Actually there’s no reasoning at all. The assumption that CO2 causes temperature rise is debunked by the ice core records.

        • Nylo
          Posted Sep 17, 2008 at 6:57 AM | Permalink

          Re: John A (#39),

          No, none of that makes sense. The CO2 only began to rise after many centuries of warming, so couldn’t contribute to the warming.
          There is no evidence that “major league players” disappeared, otherwise we’d see this in the ice core record.
          Also the CO2 did not slow the cooling, because the temps fell just as quickly while CO2 continued to rise as it did when CO2 began to fall.
          You have cause and effect backwards.

          I will try to explain why a positive feedback cannot be discarded, with an example. Numbers are arbitrary, just to give you the idea.

          T1 >> A strong forcing, not related to CO2, appears. With this forcing, the new planetary equilibrium temperature could rise 4 degrees. The planet starts warming.
          T2 >> The oceans have already warmed quite a bit (say, 2 degrees) and they start to put CO2 into the atmosphere at significant rates. This increase of CO2 creates an aditional positive feedback which depends on how much it increases.
          T3 >> The temperature is now +4 degrees, but with the current atmospheric CO2 ammount, the new equilibrium would be at +5, so the planet keeps warming, now due to the GHGs.
          T4 >> With a temperature of +5 degrees, the initial forcing disappears, and the new equilibrium temperature becomes, say, +1 degrees compared to the initial temperature, due to the increased GHG concentrations. Because the planet is hotter than equilibrium, it starts to cool. However the planet is still hot, the oceans are hot, and the atmospheric CO2 concentration has not stabilised. It continues to increase because the sea is still too hot for the current atmospheric CO2 concentration and therefore it is still a source of CO2. The cooling will be slower than it would be without the GHGs, because we are only 4 degrees far from the new equilibrium, not 5.
          T5 >> With a temperature of +3 degrees, now the oceans are cold enough to start absorbing CO2 instead of releasing it. The CO2 concentration starts to reduce.
          T6 >> The temperature is +1 degree, but it is no longer the equilibrium temperature because GHGs have reduced their concentration. So it keeps going down.
          T7 >> Back to the initial point.

        • Nylo
          Posted Sep 17, 2008 at 7:06 AM | Permalink

          Re: John A (#39),

          No, none of that makes sense. The CO2 only began to rise after many centuries of warming, so couldn’t contribute to the warming.
          There is no evidence that “major league players” disappeared, otherwise we’d see this in the ice core record.
          Also the CO2 did not slow the cooling, because the temps fell just as quickly while CO2 continued to rise as it did when CO2 began to fall.
          You have cause and effect backwards.

          I will try to explain why a positive feedback cannot be discarded, with an example. Numbers are arbitrary, just to give you the idea.

          T1: A strong forcing, not related to CO2, appears. With this forcing, the new planetary equilibrium temperature could rise 4 degrees. The planet starts warming.
          T2: The oceans have already warmed quite a bit (say, 2 degrees) and they start to put CO2 into the atmosphere at significant rates. This increase of CO2 creates an aditional positive feedback which depends on how much it increases.
          T3: The temperature is now +4 degrees, but with the current atmospheric CO2 ammount, the new equilibrium would be at +5, so the planet keeps warming, now due to the GHGs.
          T4: With a temperature of +5 degrees, the initial forcing disappears, and the new equilibrium temperature becomes, say, +1 degrees compared to the initial temperature, due to the increased GHG concentrations. Because the planet is hotter than equilibrium, it starts to cool. The cooling will be slower than it would be without the GHGs, because we are only 4 degrees far from the new equilibrium, not 5. However the planet is still hot, the oceans are hot, and the atmospheric CO2 concentration has not stabilised. It continues to increase because the sea is still too hot for the current atmospheric CO2 concentration and therefore it is still a source of CO2.
          T5: With a temperature of +3 degrees, now the oceans are cold enough to start absorbing CO2 instead of releasing it, given the current CO2 concentration, so the CO2 concentration starts to reduce.
          T6: The temperature is +1 degree, but it is no longer the equilibrium temperature because GHGs have reduced their concentration. So it keeps going down.
          T7: Back to the initial point.

  21. steven mosher
    Posted Sep 17, 2008 at 12:30 AM | Permalink | Reply

    RE 17. Reminds me of Slothrop in Gravity’s rainbow and his response to imipolex G.

  22. Lost and Confused
    Posted Sep 17, 2008 at 12:42 AM | Permalink | Reply

    This is not really relevant to the discussion, but the links at the end of this post on the front page are inside the quote box instead of outside it. It is a minor nit, but it is worth fixing.

  23. Nylo
    Posted Sep 17, 2008 at 1:05 AM | Permalink | Reply

    I quote myself,

    we cannot know how strong the warming would have been with it

    I obviously meant without.

  24. Phil
    Posted Sep 17, 2008 at 1:11 AM | Permalink | Reply

    From: http://arxiv.org/abs/0804.1126, pg. 8 (referenced in Hansen’s testimony):

    Subduction of carbon-rich crust was surely a large source of CO2 outgassing and a prime cause of global warming, which peaked 50 My ago (Fig. 3b) with the Indo-Asian collision. CO2 must have then decreased due to a reduced subduction source and enhanced weathering with uplift of the Himalayas/Tibetan Plateau [51]. Since that time the Indian and Atlantic Oceans have been the major depocenters for carbon, with subduction of carbon-rich crust limited mainly to small regions near Indonesia and Central America [47].

    The claims that are in bold above would seem to be a kind of logical positive feedback mechanism. The hypothesis that is to be proved (i.e. that CO2 causes global warming) is used to explain the rise in temperature in the Cenozoic, without citing any basis other than “surely”(in italics). Then, the rest of the explanation follows with multiple studies and citations. Thus, the hypothesis is its own initial premise, much as increased CO2 is both a cause and and effect of global warming. Positive feedback.

    • bender
      Posted Sep 17, 2008 at 5:28 PM | Permalink | Reply

      Re: Phil (#37),
      That is not quite right, Phil. There is presumed to be a forcing effect caused by exposure of carbonate rock to the atmosphere. This continental forcing then triggers the CO2 feedback that you mention. Quote:

      Also the rate of weathering (the primary long-term sink of surface carbon) is a function of the rate at which fresh rock is exposed by mountain building associated with plate tectonics.

      Specifically, during the period 60 My BP (60 million years before present) to 50 My BP India was plowing north rapidly (20 cm per year) through the Tethys Ocean and in the process subducting carbonate-rich ocean crust, causing atmospheric CO2 to increase.

      Does IPCC AR4 talk about rock exposure as a forcing agent? How new is this idea?

      • bender
        Posted Sep 17, 2008 at 6:26 PM | Permalink | Reply

        Re: bender (#127),
        Clarification:
        tectonic vulcanism = CO2 source (via atmospheric emissions)
        tectonic uplift mtns = CO2 sink (via rock weathering)

        • bender
          Posted Sep 19, 2008 at 3:39 PM | Permalink

          Re: bender (#129),
          IPCC AR4:

          Changes in CO2 on these long time scales are thought to be driven by changes in tectonic processes (e.g., volcanic activity source and silicate weathering drawdown; e.g., Ruddiman, 1997).

          Ruddiman, W.F. (ed.), 1997: Tectonic Uplift and Climate Change. Plenum Press, New York, 535 pp.

          [India collision with Asia preventing runaway warming in PETM?]

      • Phil
        Posted Sep 17, 2008 at 11:02 PM | Permalink | Reply

        Re: bender (#127) and bender (129),

        In my Phil #37, I wrote: “The claims that are in bold above…,” which is a typo. Please correct that to “The claim that is in bold above…”

  25. Sylvain
    Posted Sep 17, 2008 at 1:29 AM | Permalink | Reply

    What has changed recently is the steady global warming, at
    a rate of about 0.2°C per decade, which has brought global temperature
    close to the peak level of the current interglacial period. This trend is
    shifting climate zones and isotherms (lines of a given average
    temperature) poleward, at a rate of about 50-60 kilometers

    I would believe that this claim of 0.2C is based on instrumental temp. Is there any scientific basis to compare instrumental temp to proxies temp? (Assuming that instrumental temp don’t go beyond a few centuries back.)

    Shouldn’t the variation be compared proxies to proxies?

  26. Don
    Posted Sep 17, 2008 at 4:07 AM | Permalink | Reply

    Anthony Watts has a relevant post – see

    http://wattsupwiththat.wordpress.com/2008/09/11/rethinking-carbon-of-the-past-scientist-uncovers-miscalculation-in-geological-undersea-record/

    From the primary researcher, “This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth’s history. If the approach does not work over the past 10 million years, then why would it work during older time periods? As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth’s geological history will have to be adjusted.”

  27. Michael Smith
    Posted Sep 17, 2008 at 4:32 AM | Permalink | Reply

    Hansen gives the standard explanation for the glacial/interglacial cycle as follows:

    The direct forcing due to orbit changes is negligible, the annual mean
    perturbation of the Earth’s energy balance never exceeding 0.2 W/m2
    averaged over the planet. But the ice-albedo and GHG feedbacks each
    cause (approximately equal) perturbations of several W/m2 (Fig. 2B).
    Together these two feedbacks fully account for the global temperature
    swings from glacial to interglacial conditions (Fig. 2C), with a climate
    sensitivity of 3/4°C per W/m2 of forcing, or 3°C for doubled CO2 forcing.

    Here is what doesn’t make sense to me. If the initial direct forcing due to orbit change is “negligible”, and the feedback mechanisms (GHG increase and albedo change) “fully account for” the temperature rise, then we should see an acceleration of temperature rise as these feedbacks kick in. But all of the graphs I’ve seen show a relatively steady rate of temperature rise both before and after the increase in CO2 — implying that the effects of the feedbacks are of the same magnitude as the effect of the initial forcing.

  28. SOM
    Posted Sep 17, 2008 at 4:38 AM | Permalink | Reply

    Hansen said “The single most pertinent number emerging from Cenozoic climate studies is the level of atmospheric CO2 at which ice sheets began to form as the planet cooled during the past 50 million years. Our research suggests that this tipping point was at about 450 ppm of CO2″.

    So that’s the tipping point on the way down where CO2 level drop was lagging temperature drop. What was the global average temperature when that tipping point happened and how does it compare to current temperatures?

    Then in his Figure 1 Hansen shows Antarctic glaciation when deep ocean temperature was approx 3deg C and later the N. hemisphere ice sheet forming at say 2.5 deg C deep ocean temperature. Presently it looks like deep ocean temperature is barely above 0 deg C.

    So if anthropic CO2 is causing warming how long and how many ppm under Business As Usual before fig 1 is reversed and the NH ice sheet melts?

    Hansen says nothing about this but this seems to me to be the most relevant future tipping point to the Kingsnorth case.

  29. Posted Sep 17, 2008 at 4:41 AM | Permalink | Reply

    snip -policy

  30. Richard
    Posted Sep 17, 2008 at 4:51 AM | Permalink | Reply

    The problem is that neither CO2 nor (more importantly) water vapor are homogeneously distributed. The desire to treat the climate as a homogeneous system is where Hanson’s arguments break down:

    For a given “global” average temperature and humidity an infinite variety of temperature and humidity distributions can occur. Each distribution can have widely varying effects. For example, in the case of cloud cover, it is well established that some clouds can act to increase local warming while others can act to decrease warming. Different temperature and humidity distributions will produce different types of clouds and therefore different warming or cooling effects.

    Lumping everything together into a simple energy balance misses too many important effects.

    There is no mention of the fact that CH4 concentrations seem to have leveled off since around 2000.

  31. Posted Sep 17, 2008 at 5:08 AM | Permalink | Reply

    Steve

    I hope you do not think my initial comments are policy and snip them, but the context of the trial surely needs some clarification. The defendants were accused of criminal damage (and admitted the actual deed). In that it is the latest in a series where protestors have with impunity destroyed GM crops and entered a nuclear submarine facility.

    As a British citizen I pay some three times more for my petrol than over the pond. Our fuel bills are at least double. A report out today (but already known for years) is that we will have an enormous energy gap in 4 to 8 years as our coal and nuclear stations are decommissioned. It is a matter of fact that it is impossible for renewables to replace them within 20 years let alone become the base supply. Much of our fuel comes from countries whose rulers dont like us, yet we have hundreds of years worth of coal locked in our land.

    Defending someone on the basis that they are preventing a greater damage seems like the sort of semantics you are so good at deconstructing. By that basis if I disagree with 4by4 cars or indeed any cars, that surely doesnt give me the right to damage them because of my belief I am doing something for a greater good?

    In that context can I please comment as follows;

    1) Hansen was testfying because of his reputation (his cv was posted) so de facto this was a state scientist not a private individual. As such, quasi state sponsored approval of criminal damage may seem to many to have other repercussions.
    2) The comment about sea levels rising at 3cm a year has been called a ‘lie’ by Prof Morner. In my profesional capacity involved with an agency of the UK government, sea level rise is a hugely debatable contention. Data from the Proudman observatory taken over an extended period do not support this worldwide level of increase. Other agencies such as in Holland and Denmark do not support it.
    There are so few data observation points anyway, that water level data is surely as anecdotal as when I make references to actual historical events demonstrating sea levels over extended periods in mans recent history? The scientists can’t have it both ways.
    3) Surely man adding to co2 at the rate of 2ppm per year is in excess over what many others say and ignores the greater contribution from Nature?

    4) The historic pre industrial level of around 250ppm has been measured by a variety of sources and is sometimes said to be much closer to the current levels than often stated.

    5) I and no doubt others have posted studies of estimated temp rises if co2 increases, and the range -including IPCC scientists and Hansen- vary wildly even though the same data is used.
    6) The past warming events again seem to have been ignored. Complex theoretical computer models seem to have the ascendancy over observable recorded facts. The jury must have been left with the impression that the modern era is unique in its warmth.

    7) Both Science and New Scientist- and Hansen in his testimony- confirm that GHG rise long after temperatures increase. I know that Hansen dismisses this, but if anyone can explain why cause and effect seems to be suspended in this instance I would be pleased to hear it.

    Personally I think proving that the earths past climactic events are real is essential, on the basis that ‘we have been this way before.’ If scientists then want to start arguing that its different this time we can then have a sensible discussion about the earths precession, or our orbit, which combined with a minor GHG they think will cause problems.

    I am far more concerned about inevitable dramatic power shortages in the UK and the fact that we are vulnerable to unfriendly powers than AGW which- despite the medias view-is still hotly contested.

    I have taken this thread as being for comments rather than a barrage of data so have not posted supporting links, which I will do if anyone feels it relevant.

    Tony Brown

    • Dave Dardinger
      Posted Sep 17, 2008 at 7:36 AM | Permalink | Reply

      Re: Tony Brown (#45),

      3) Surely man adding to co2 at the rate of 2ppm per year is in excess over what many others say and ignores the greater contribution from Nature?

      Unfortunately this sort of confusing statement is too common by skeptics and helps put us in a bad light. You’re conflating the CO2 flux with the CO2 increases. The increases are from sources outside the biosphere. Plants absorb CO2 and later decay of plants release it. This means that there is a large reservoir of C / CO2 which recycles regularly. But it loses some to long-term storage and gains some from weathering. Human burning of fossil fuel is a one-way change and only slowly comes into equilibrium. This will primarily come from storage in the deep ocean.

      However there is a mistake, IMO, in the warmer position which is the assumption that we’re going to warm the deep oceans from CO2 additions. But I’ll make that a separate message.


      Steve:
      Let’s leave this particular issue on this thread at this point. No further discussion of it please.

      • Dave Dardinger
        Posted Sep 17, 2008 at 1:33 PM | Permalink | Reply

        Re: Dave Dardinger (#57),

        Tony Said:

        3) Surely man adding to co2 at the rate of 2ppm per year is in excess over what many others say and ignores the greater contribution from Nature?

        I replied:

        Unfortunately this sort of confusing statement is too common by skeptics and helps put us in a bad light. You’re conflating the CO2 flux with the CO2 increases.

        You admonished:

        Steve: Let’s leave this particular issue on this thread at this point. No further discussion of it please.

        But in your second link above it says:

        A lot of the evidence today – from both Dr Meaden and Professor Hansen – was quite technical, looking at the parts per million of carbon dioxide concentrations in the atmosphere, tipping points and feedback mechanisms.

        So what the hay?? This isn’t RC, at least not last I looked. If we can’t talk about the very subject that was being discussed in the trial, what are we supposed to talk about?

  32. Nick
    Posted Sep 17, 2008 at 5:32 AM | Permalink | Reply

    Hansen is quoted thus:

    “If we carry on with business as usual, we’ll cause the extinction of one million species. Proportionately, several hundred of these species extinctions could be associated directly with Kingsnorth power station. ”

    From a scientific point of view, that is a totally baseless observation. Not the use of the word “we’ll”, i.e we WILL cause the extinction. There is no scientific evidence of which I am aware that can link power generation with extinctions. Neither is their any basis for his choice of figures. If he’s that clever, why not 750,563 or 1,234,632 extinctions? He plucked “one million” and “several hundred” from thin air for purely emotive reasons.

    It’s a pity the prosecution didn’t ask him to list them.

  33. Nick
    Posted Sep 17, 2008 at 5:33 AM | Permalink | Reply

    Sorry – corrected version:

    Hansen is quoted thus:

    “If we carry on with business as usual, we’ll cause the extinction of one million species. Proportionately, several hundred of these species extinctions could be associated directly with Kingsnorth power station. ”

    From a scientific point of view, that is a totally baseless observation. Note the use of the word “we’ll”, i.e we WILL cause the extinction. There is no scientific evidence of which I am aware that can link power generation with extinctions. Neither is there any basis for his choice of figures. If he’s that clever, why not 750,563 or 1,234,632 extinctions? He plucked “one million” and “several hundred” from thin air for purely emotive reasons.

    It’s a pity the prosecution didn’t ask him to list them.

  34. Posted Sep 17, 2008 at 6:00 AM | Permalink | Reply

    Hansen said in his evidence: “Climate forcings are measured in Watts per square meter (W/m2)
    averaged over the Earth. If the amount of CO2 in the air were doubled it
    would reduce infrared emission to space by 4 W/m2. Thus doubled CO2 is
    a forcing of 4 W/m2. The Earth absorbs ~ 240 W/m2 of energy from the
    sun, so doubled CO2 is equivalent to increase of solar irradiance by almost
    2 percent”.

    Is this true? I think not:

    The radiative forcing (RF) data in Table 2.1 of Solomon et al. (IPCC, 2007) is used by Australia’s Ggarnaut report (www.garnautreview.org.au) to put the CO2e level of the total atmospheric concentration of greenhouse gases at “about” 455 ppm in 2005. That Report does not explain how it reached this figure, but it seems likely it adopted the following procedure using a log linear relationship between CO2 concentration and energy retention. The IPCC implies that its figure for the radiative forcing of CO2 in 2005 was 1.66 Watts per square metre (W m-2) for the current CO2 concentration of 379 ppm, but it seems plausible that the Report related this RF to the increase in the concentration from the pre-industrial level of 280mm to c.380 ppm. “The increase from 280 to 380 represents 0.44 doublings (2^n = 380/280 = 1.357. Take logs of both sides: n log 2 = log 1.357 from which n = log 1.357/log 2 = 0.44). That means doubling CO2 would contribute 1.66/0.44 (W m-2) = 3.77 (W m-2). If the total increase from all greenhouse gases was 2.63 (W m-2), that would represent 2.63/3.77 doublings = 0.7 doublings. Thus 2^0.7=1.62=new CO2 concentration/280, from which it follows that the new equivalent CO2 concentration would be 1.62 * 280 = 455 ppm”, confirming the Report’s figure (personal communication, Michael Hammer, 15 September 2008). However, applying plain English and arithmetic to the IPCC data, the stated CO2 RF of 1.66 refers to the 2005 total concentration of 379 ppm, yielding RF of 0.00438 W m-2 per ppm of CO2. At that rate, the total RF of the non-CO2 gases of 0.97 W m-2 would require 221.46 ppm of CO2 for the “equivalent” RF, giving total CO2e in 2005 of 600 ppm CO2e. This is almost double Hansen’s new target of 350 ppm and all tipping points are upon us, with all Antarctic ice about to disappear tomorrow!

  35. Posted Sep 17, 2008 at 6:32 AM | Permalink | Reply

    Steve, you’re doing sterling work here, thanks; I check your site every single day and always learn something. I’ve only read a little of Hansen’s testimony but something has leapt out and surprised me. He says:

    The claim that “we cannot predict next
    month’s weather in London, so how in the world can we predict the effect
    of human-made greenhouse gases in 50 years!” is a nonsensical
    statement, failing to recognize the difference between chaotic weather
    fluctuations and the deterministic response of the Earth to a large change
    in the planet’s energy balance.

    Science begins in reason, continues in observation and concludes in reason. The observations and reasonings of science are expressed through language, so it behoves the scientist to learn it perfectly, or science will suffer.

    So we see with this scientist. He unscientifically expresses a question (beginning “how in the world…”) with the punctuation of a statement. But he goes on to call it a statement (so he must actually believe it).

    This is no small point. In failing to correctly describe what is not only under his very nose, but which he himself just created, he reveals a failure in his powers of both reason and observation. There is nothing more fundamental to his role as scientist.

    If he is careless in this, what else has he overlooked? If he demonstrates poor standards in this, where else have his methods fallen short?

    No, he has been too distracted, pressed for time or too lazy to write properly and simply didn’t care if he made mistakes. One cannot imagine such an attitude in Isaac Newton, for example.

    Unimpressive, in my opinion. Hansen has more substantial scientific criticisms being levelled at him, but this one concerns language, which concerns me. I will read the rest of the paper with care.

    Cheers,
    Richard Treadgold,
    Convenor,
    Climate Conversation Group.

  36. Geoff Sherrington
    Posted Sep 17, 2008 at 6:44 AM | Permalink | Reply

    Methane clathrate (syn hydrate). Vast quantities are estimated now –

    By some estimates, the energy locked up in methane hydrate deposits is more than twice the global reserves of all conventional gas, oil, and coal deposits combined.

    https://www.llnl.gov/str/Durham.html

    What was its distribution and contribution to air temperature in the Cenozoic? Because of the recent discovery of its extent, has it been included properly in projections, both back and forward? I suspect its mention by Dr Hansen to be a speculation, a non sequitur, like much of the rest of his evidence.

    • Geoff Sherrington
      Posted Sep 19, 2008 at 3:29 AM | Permalink | Reply

      Re: Geoff Sherrington (#50),

      To expand on methane clathrates, if there was an ice-free earth in the past, the there would have been no methane clathrates either. There are now. So it a reasonable hypothesis that methane clathrates have both formed and disappeared before the advent of the influence of Man.

      I am interested in what cooled the globe enough to allow the clathrates to form.

      If AGW is needed to start the cycle again, why was it not needed before Man? Dr Hansen is illogically objecting to the natural cycle of climate.

      • Urederra
        Posted Sep 19, 2008 at 7:53 AM | Permalink | Reply

        Re: Geoff Sherrington (#173),

        You might be interested in what wiki says about methane in the atmosphere.

        Methane in the atmosphere is eventually oxidized, producing carbon dioxide and water. As a result, methane in the atmosphere has a half life of seven years (if no methane was added, then every seven years, the amount of methane would halve).

        I wonder if Ruddiman accounted for methane half life when he exposed his “rice paddies saved us from an ice age” hypothesis.

        • DeWitt Payne
          Posted Sep 19, 2008 at 9:15 AM | Permalink

          Re: Urederra (#175),

          Yes. If methane weren’t being continuously emitted naturally (swamp gas, e.g.) there would be none in the atmosphere. The observation that led to his conclusion was that in the ice core records during interglacials methane rises to a peak and then decreases as temperature rises and falls. During this interglacial, methane rose, peaked, started to decrease and then stopped decreasing and began increasing again starting about 5,000 years ago.

  37. Nylo
    Posted Sep 17, 2008 at 7:08 AM | Permalink | Reply

    (duplicated by mistake, sorry, please delete the second one)

  38. Michael Smith
    Posted Sep 17, 2008 at 7:23 AM | Permalink | Reply

    Nylo, can you explain the inconsistency I noted in comment 41? Namely, can you explain why the rate of temperature increase seems to be the same before and after the CO2 begins to rise?

    The only way I can see for that to occur is if the feedbacks have almost exactly the same effect as the initial forcing — which Hansen denies — AND if the initial forcing “phases out” just in time for the feedbacks to “phase in”. It has to be “just in time” — otherwise we’d see one of two things: 1) a period of significantly greater rates of warming because BOTH factors would be operating — OR — 2) we’d see a period of NO warming because neither factor was operating.

    So we have to have nearly identical effects and “just right” phase-out and phase-in timing. How likely does that sound to you?

  39. Steve McIntyre
    Posted Sep 17, 2008 at 7:25 AM | Permalink | Reply

    Please do not use this thread in order to propose your own personal theories of climate change or lack of climate change. TRY to read what Hansen wrote and see if there’s anything NEW in this that hasn’t been discussed previously. As an editorial position, I’m not interested in one-paragraph personal opinions on CO2-temperature leads and lags or infrared absorption etc. Not that these aren’t important issues, it’s just that one-paragraph arguments aren’t very illuminating. So look for NEW things in this testimony or I’m afraid that I’ll shut the thread down.

    • Nylo
      Posted Sep 17, 2008 at 1:08 PM | Permalink | Reply

      Re: Steve McIntyre (#55),

      Please do not use this thread in order to propose your own personal theories of climate change or lack of climate change.

      I’m sorry Steve, I wasn’t trying to propose my own personal theories. I was only explaining how Hansen and the other alarmists understand the lag in the change of CO2 concentration with changes in temperatures, what kind of reasoning they use that allows them to claim that CO2 is a forcing in spite of the historical evidence. But it is not my theory, and in fact I don’t personally believe it. I accept that it is plausible, but I find it quite unlikely unless the CO2 contribution was very, very small compared with the other forcings.

  40. Nicholas
    Posted Sep 17, 2008 at 7:33 AM | Permalink | Reply

    This may be off topic, or may not, I’m not sure. Apologies in advance if it is.

    I buy the argument that CO2 gas can act as both a forcing, if it added directly to the atmosphere, and a feedback, if its emission into the atmosphere is in reaction to temperature.

    What I don’t get about the argument, though, is that the very argument for how this makes sense – see Nylo above – basically admits that it requires an initial forcing to explain what we see in the historical record. But my question is, what was this forcing? And if the answer is “we don’t know for sure”, then how can we be sure it isn’t the same forcing which is causing any changes in climate we may be observing today? And if the answer is “we can’t” then doesn’t that undercut the “correlation between rising CO2 and temperature proves AGW” type arguments?

  41. Richard
    Posted Sep 17, 2008 at 7:47 AM | Permalink | Reply

    The long lifetime of human-made CO2 perturbations assures that no human generation that we can imagine will need to be concerned about global cooling. Even after fossil fuel use ceases and its effect is drained from the system an ice age could be averted by chlorofluorocarbons (CFCs) produced in a single CFC factory. It is a trivial task for humanity to avert an ice age.

    I understand something like 20 years of cooling is enough to disprove the CO2/Temperature correlation thesis.

    The basic principle is that global temperature can be predicted while regional weather cannot. The mistake made here is that local effects can in fact influence the “global” forcing due to the chaotic nature of the system. For example a very large underwater volcanic event (eg the Gakkel Ridge eruptions in 1999) could quite feasibly disturb the regional oceanic circulation.

    The Hansen assumption is that regional weather and oceanic circulations are in equilibrium and can therefore be neglected. The reality is that such an equilibrium cannot really exist. There are an enormous number of phemonomena that interact on a wide range of time scales. We can look at different quantities over different time periods and try to explain what is going on but we will inevitably fail for three reasons:

    i) we do not have enough detailed information about the low frequency forcing from the past

    ii) we do not have enough information about the present to predict local phenomena in great detail (even daily weather forecasts are quite generalised)

    iii) we cannot accurately predict important future events (eg volcanoes, fires etc…), external factors (sun intensity evolution, meteor strikes etc…) or key interactions (relationship between different oceanic oscillations, atmospheric oscillations etc…) each of which has the potential to modify the forcing associated with the so called global energy balance.

  42. Steve McIntyre
    Posted Sep 17, 2008 at 7:50 AM | Permalink | Reply

    I’ve asked people not to advance personal theories and stick to the document. This thread is on a very short fuse if people aren’t going to do this.

  43. JamesG
    Posted Sep 17, 2008 at 7:50 AM | Permalink | Reply

    The best way to treat the CO2 strong feedback theory is on the basis of probabilities. We have theory A, which says that the heating effect of GHG’s via feedback is next to negligible. Theory B (the strong CO2 feedback) requires a sudden stop in the CO2-amplification process in order for the supposed weak trigger to overcome it and so let the cooling period restart. Due to the lack of a good explanation for this onset of cooling, an objective scientist should select the fully formed theory A as more plausible unless good evidence was forthcoming for the alternative half-theory B. Hansen, of course, already knows that CO2 sensitivity is high because the heating half-cycle of the paleo data tells him so. It’s totally absurd.

  44. Mark Duffett
    Posted Sep 17, 2008 at 8:37 AM | Permalink | Reply

    As a geologist/geophysicist, a couple of Hansen’s statements jumped out at me. One was

    “by the early Cenozoic the continents were close to their present latitudes”

    In the case of Australia and India (the two that jumped instantly to my mind), that’s not true. As Hansen himself says only a few paragraphs down,

    “during the period 60 My BP (60 million years before present)to 50 My BP India was plowing north rapidly”

    (note the Cenozoic started 65 million years ago).

    And Australia was 30 degrees south of its current location. That’s important, because this is the reason why there was no circum-Antarctic ocean current in the early Cenozoic. Which means that heat transport from equator to poles was much more efficient – hence palm trees growing in Greenland and Patagonia, and a forested Antarctica (all of which were in similar latitudes to today).

    This brings me to the second statement that caught my eye:

    “it is the rate of subduction of carbonate-rich ocean crust beneath moving continental plates that determines the rate of volcanic emission of CO2.”

    That assertion is, to say the least, questionable. Hansen uses this to paint the consequences of India-Asia collision as being all about CO2. The post-Eocene cooling may well have resulted from this event and associated Himalayan uplift, but this idea that it’s all about the CO2 is a new one on me. Rather, my understanding has always been that the resulting changes in oceanic and atmospheric circulation were the main climate driver at this epoch.

    Similarly, it was only when a volumetrically significant seaway opened between Australia and Antarctica at around 45 m.y.b.p. that the circum-Antarctic current was able to get going. Heat transport from the equator was thus suppressed, and the glaciation of Antarctica (and a new phase of global cooling) began.

    In summary, it seems to me that in his evidence, Hansen has only addressed changes in the distribution of continents in terms of albedo effects, rather than oceanic and atmospheric circulation. Conversely, he has exaggerated the effect of plate tectonic processes on atmospheric CO2 well beyond what I understand to be the norm of understanding of this subject.

    • bender
      Posted Sep 17, 2008 at 9:10 AM | Permalink | Reply

      Re: Mark Duffett (#64),

      this idea that it’s all about the CO2 is a new one on me. Rather, my understanding has always been that the resulting changes in oceanic and atmospheric circulation were the main climate driver at this epoch.

      This surprised me too. I don’t know my paleoclimatology. But I also thought this was about tropical-polar ocean circulation and whether or not there was a continental land mass located at a pole. Does this come from the primary literature – this idea of CO2 as a Cenozoic driver?

    • Phil
      Posted Sep 17, 2008 at 9:15 AM | Permalink | Reply

      Re: Mark Duffett (#64), Significant Cenozoic global warming has been attributed by Hansen almost entirely to CO2, although his premise is unsupported in the article and questioned by Mark. So what was the cause of the Cenozoic global warming?

  45. Posted Sep 17, 2008 at 8:41 AM | Permalink | Reply

    I have now read every word of all the documents. Dave #57 has slightly misinterpreted my comments (sorry-perhaps my clumsy phrasing) but to correct my meaning would I think be counter to Steves aims of this thread.

    Power stations are some 20% of Co2 emissions. Solid fuel some 35% of that. The Uk’s coal fired emissions some 3% of that. So we are responsible for a fraction of 1% of all man made emissions. To say coal is responsible for 1 million lost species can not be substantiated and to attribute several hundreds of that loss directly to this coal fired power station complete fabrication.

    What strikes me all the way through all the witness statements and Greenpeaces summary, is how supposition is put forward as fact.

    ‘Present rates of temp rise are unprecedented’.
    ‘Sea level rises are increasing exponentially’

    Some are distinctly unscientific. The comment by Zac goldsmith that the ice cap in 2007 is only 50% of that in 1980 may be true, as may the Inuit ladies comment that ‘I have witnessed the changes during my lifetime.’ However the size of the ice cap in say 1932 or 1032 or in Roman times is not mentioned, and whilst it may be unprecedented in one persons life time, it is unlikely to have been so in her forefathers times when they competed with the Vikings and their predecessors -The Thule-colonised Ellesmere island.

    What I find disturbing in this whole debate is that there is not one word anywhere that actually admits to there being a variety of very well documented examples of climate change over the last 5000 years-without any help from humanity.

    If I was a jury member-setting aside this is a curious defence for criminal damage-I would listen to all this apparently factual evidence and unless someone was whispering in my ear about the Bronze age, Romans, Vikings et al I would find the defendants not guilty.

    Is it unreasonable to ask that those believers in AGW should concede we have been this way before and tell us why this current episode is different? Until they do (not one word in around 30000 words of written testimony) it is difficult to move the debate on

    Tony Brown

  46. Julian Flood
    Posted Sep 17, 2008 at 8:52 AM | Permalink | Reply

    QUOTE September 17th, 2008 at 7:25 am

    Please do not use this thread in order to propose your own personal theories of climate change or lack of climate change. TRY to read what Hansen wrote and see if there’s anything NEW in this that hasn’t been discussed previously.UNQUOTE

    The attribution of raised CO2 to anthropogenic emissions is a straight assertion — there’s no attempt to display the science which, judging from the rest of it, he would have been happy to do had he been confident.

    Or perhaps it’s now so old hat, like 2 – 4.5 deg/CO2 doubling, that one no longer needs even to mention it.

    JF

  47. bender
    Posted Sep 17, 2008 at 8:57 AM | Permalink | Reply

    The Earth was much warmer than today in the early Cenozoic. In fact it was so warm that there were no ice sheets on the planet and sea level was about 75 meters higher.

    So in the grand scheme of things, we are more or less colder now than ever before … yet we are going to try to prevent any further warming? And we’re going to do this at any cost? Doesn’t that sound incredibly expensive and highly impossible?

    We live on a Cenozoic planet. And right now it happens to be very cold. Does it make sense to set the thermostat at a position where it, realistically, can not be maintained? Wouldn’t it be more reasonable to set it in the middle somewhere? And then adapt to the consequences?

    I guess this all depends on whether you believe temperature can run away. What capped Cenozoic warming? A lucky negative forcing or a deterministic negative feedback?

    • DeWitt Payne
      Posted Sep 17, 2008 at 9:23 AM | Permalink | Reply

      Re: bender (#68),

      So in the grand scheme of things, we are more or less colder now than ever before …

      Well, maybe not ever. According to this graph it was colder 450 million years ago.

      Steve: as I noted above, the evidence for the early Icehouse period needs to be looked at very closely; it’s a newish theory.

  48. Steve McIntyre
    Posted Sep 17, 2008 at 9:05 AM | Permalink | Reply

    Comment #64 is the sort of discussion that I want to have. IT’s a topic that we haven’t discussed and is interesting.

    ONce again, if you feel like opining on a matter that’s been discussed endlessly, please DON’T.

  49. Steve McIntyre
    Posted Sep 17, 2008 at 9:12 AM | Permalink | Reply

    The gradual cooling of the planet over a 50 million year period is really a very interesting phenomenon and little discussed. The last ice age appears to have been remarkably cold.

    A question: on Hansen’s theory attributing the gradual colding to reduced CO2, was the earth on its way to being a permanent icehouse under his theory? With cycles gradually getting colder and colder with more depleted CO2? Just asking, not suggesting.

    Also I’d be interested in geological opinions on the solidity of evidence for Icehouse Earth periods in Deep Time. This is a pretty new theory and some of the grological evidence looks to me like it might bear alternative interpretations. But I don’t know the field. If any geologist readers can opine, I’d appreciate it.

    • bender
      Posted Sep 17, 2008 at 9:19 AM | Permalink | Reply

      Re: Steve McIntyre (#72),

      on Hansen’s theory attributing the gradual colding to reduced CO2, was the earth on its way to being a permanent icehouse under his theory?

      I asked “what capped the Cenozoic warming?” You ask “is there anything that caps the modern cooling?”. There are two sides of the same coin: what regulates climate? What prevents runaway on either side, top & bottom?

      I can’t answer. Can only ask.

    • bender
      Posted Sep 17, 2008 at 10:43 AM | Permalink | Reply

      Re: Steve McIntyre (#72),

      on Hansen’s theory attributing the gradual colding to reduced CO2, was the earth on its way to being a permanent icehouse under his theory?

      Hansen:

      But shouldn’t Earth now, or at some point, be headed into the next ice age? No. Another ice age will not occur, unless humans go extinct. Orbital conditions now are, indeed, conducive (albeit weakly6) to initiation of ice sheet growth in the Northern Hemisphere But only a small amount of human-made GHGs are needed to overwhelm any natural tendency toward cooling.

      So it matters what time in the past you are inkoving when you ask “was the earth on its way …”. In the absence of anthropogenic GHGs the answer, when referring to the past, appears to be … ‘yes’!

      Which would be quite an ironic admission: burning fossil fuels saved us from the perilous fate of the icehouse.

      • DeWitt Payne
        Posted Sep 17, 2008 at 3:31 PM | Permalink | Reply

        Re: bender (#86),

        Which would be quite an ironic admission: burning fossil fuels saved us from the perilous fate of the icehouse.

        According to Ruddiman (not a direct link to the literature), it was actually the release of methane from rice paddies and other forms of agriculture starting about 5,000 years ago that prevented the same sort of fairly rapid decay in temperature seen in the Vostok ice core record of previous interglacials.

    • bender
      Posted Sep 17, 2008 at 3:28 PM | Permalink | Reply

      Re: Steve McIntyre (#72),

      was the earth on its way to being a permanent icehouse under his theory?

      An unasnwered question at RC:

      Would GCMs predict another ice age if you could turn off the human CO2 contribution in the models and had the computing power to simulate the next 50,000 years?

    • Mark Duffett
      Posted Sep 18, 2008 at 7:44 AM | Permalink | Reply

      Re: Steve McIntyre (#72),

      Steve, I think you mean the theory known as ‘Snowball Earth’ rather than ‘Icehouse Earth’. The latter is more a non-controversial shorthand term for the cooler mode of a global climate dichotomy, as seen here. It’s basically defined by the presence of polar ice sheets, so the present epoch is one of Icehouse Earth.

      The (Neoproterozoic, i.e. ~650 Ma.) Snowball Earth idea, I’ve just discovered, actually has its own website, which looks at first glance to be a good though obviously biased introduction. My own take is that the theory is accepted in some form by the majority of practitioners in the field, but far from universally. Much current work centres on how much if any open ocean was present in low latitudes. It’s attractive in that it explains several lines of otherwise problematic evidence (near-ubiquitous glacial sediments, including many in paleo-low latitudes as indicated by paleomagnetic studies, overlain by equally ubiquitous ‘cap carbonates’ (resulting from a CO2 insolubility spike at Snowball Earth termination). There are many ideas as to what caused its onset, including true polar wander and super-mountain-chain uplift.

      I’ll probably be able to give a better precis after going to a talk by the main populariser of the theory, Paul Hoffman. He’ll be speaking at the next meeting of the Geological Society of Australia (Tasmanian Division), Monday 29th September at the University of Tasmania (all welcome ;-))

  50. bender
    Posted Sep 17, 2008 at 9:12 AM | Permalink | Reply

    #71 was a crosspost with #70.

  51. tty
    Posted Sep 17, 2008 at 9:15 AM | Permalink | Reply

    Hansen has completely misunderstood how ice ages occur. He argues that the total change in insolation caused by orbital changes is minimal (which is true), and therefore CO2 is the main driver of climate. However changes between glaciations and interglacials are caused by changes in the *distribution* of sunlight, which is far from negligible. When summer insolation in high northern latitudes increase, northern hemisphere ice-sheets melt (and a CO2 increase follows) when insolation decreases, new ice-sheets form. Incidentally similar changes in the southern hemisphere seem to have negligible effect, due to the great stability of the Antarctic ice-sheet.

    He also systematically understates temperature changes in the geologic past. For example that the global temperature during the previous interglacial was less than 1 degree warmer than the present one. Actually it isn’t easy to even find a place where the temperature wasn’t more than 1 degree warmer then (parts of the Mediterranean Basin might qualify).
    In the same way he exaggerates the sea-level rise then (4-6 meters). Actually studies on tectonically stable coasts far from ice-sheets (Barbados, Gawler Craton, Coorong coastal plain) indicate that 2 meters is a more realistic figure.

    His whole description of the last 60 million years is slanted in the same way. It is based on the premise that CO2 and only CO2 drives climate, and everything else has to be fitted to this assumption. So, in Hansen’s world Himalaya has already started to erode at a time when the first whales were swimming in a shallow tropical sea where Himalaya is today. In the same way the abrupt climate shift in the early Oligocene is glossed over (despite being one of the very few good examples of a probable climatic “tipping point” in geologic history). The reason for this is obvious, there is general agreement that it was caused by the opening of the Tasman Sea and the inception of circumpolar circulation in the Southern Ocean, which isolated Antarctica from warm low-latitude air. So, having nothing to directly to do with CO2 it is simply ignored. And so on and so on.

  52. George Tobin
    Posted Sep 17, 2008 at 10:03 AM | Permalink | Reply

    Given Hansen’s analysis shouldn’t we be trying to prevent more continental drift with the concomitant release of GHGs when plates collide? Let’s not repeat the mistakes of the Cenozoic and let tectonics run wild.

    Who presided over this trial? His Lordship Lance Ito, QB?

    Allowing all this rambling crap into the trial baffles me. Even if the defendants were sincere and and even if their beliefs were deemed well-informed, how exactly is that a cognizable defense? Consider this: I happen believe the world’s governments are spending too much on useless climate modeling while ignoring AIDs, hunger, political oppression, deforestation and Darfur. So if I burn Hansen’s office in protest, shouldn’t I also beat the rap? I would be sincere, well-informed and unquestionably correct both morally and factually. And, come to think of it, I have some free time coming up….

  53. bender
    Posted Sep 17, 2008 at 10:08 AM | Permalink | Reply

    was the earth on its way to being a permanent icehouse under his theory?

    very closely related question:

    was the earth on its way to being a temporary icehouse under his theory?

  54. bender
    Posted Sep 17, 2008 at 10:14 AM | Permalink | Reply

    If the earth has two stable states – icehouse vs waterworld – then choosing to set the thermostat at some intermediate level would lead to a permanent state of climtic hypochondria as we attempt to regulate temperature in a region of tremendous inherent instability.

    If the earth has two stable states – icehouse vs waterworld – then we’re probably best off picking the least risky one to which we are best adapted.

    Seems like an important theory to have clarified.

  55. DG
    Posted Sep 17, 2008 at 10:15 AM | Permalink | Reply

    How does this new and improved version of Hansen’s court testimony square with his “smoking gun” 2005 article that IPCC formed its basis for “proof” of anthropogenic global warming?

    Earth’s Energy Imbalance: Confirmation and Implications

    The abstract reads:

    Our climate model, driven mainly by increasing human-made greenhouse
    gases and aerosols, among other forcings, calculates that Earth is now absorbing
    0.85 T 0.15 watts per square meter more energy from the Sun than it
    is emitting to space. This imbalance is confirmed by precise measurements of
    increasing ocean heat content over the past 10 years. Implications include (i) the
    expectation of additional global warming of about 0.6-C without further change
    of atmospheric composition; (ii) the confirmation of the climate system’s lag
    in responding to forcings, implying the need for anticipatory actions to avoid
    any specified level of climate change; and (iii) the likelihood of acceleration of
    ice sheet disintegration and sea level rise.

    No more arm waiving.
    What are the underlying physics whereby ~2 ppm annual increases in atmospheric CO2 results in oceans accumulating
    .85 watts per meter square more energy from the sun than is emitting to space.

    What are the calculations that explain how CO2 warms the oceans more than direct solar radiation.

    Nowhere in Hansen et al 2005 do they mention CO2 lagging temperature or ocean outgassing. Nor do they address water vapor feedback, solar radiation or cloud dynamics.

    Further, according to the updated Argo data, OHC stopping increasing in 2003. Where is the missing heat?

    This is looking more and more like a perpetuum mobile.

    • bender
      Posted Sep 17, 2008 at 10:21 AM | Permalink | Reply

      Re: DG (#82),

      What are the calculations that explain how CO2 warms the oceans more than direct solar radiation.

      When this question is asked at RC, it is ridiculed rather than replied to.

    • bender
      Posted Sep 17, 2008 at 10:35 AM | Permalink | Reply

      Re: DG (#82),

      How does this new and improved version of Hansen’s court testimony square with his “smoking gun” 2005 article that IPCC formed its basis for “proof” of anthropogenic global warming?

      There is little basis for comparison, as the testimony mentions energy imbalance only in qualitative terms.

    • bender
      Posted Sep 17, 2008 at 12:32 PM | Permalink | Reply

      Re: DG (#82),

      according to the updated Argo data, OHC stopping increasing in 2003

      What’s your source? And how does that square with this:
      Improved estimates of upper-ocean warming and multi-decadal sea-level rise

      discussed at RC?
      That “OHC stopped increasing in 2003″ implies a persistent trend. What makes you think it will persist? And why choose 2003 as a start point in the trend analysis? Is that not cherry-picking?

      • DG
        Posted Sep 18, 2008 at 8:18 AM | Permalink | Reply

        Re: bender (#94),

        I’ve been following the OHC issue for the last 1 ½ years and am well aware of the Lyman correction. If I wanted snarky replies, obfuscation and condescension RC does that well enough.

        The “discussion” at RC references the Domingus paper that ends their analysis in 2003. RC cleverly avoids mentioning the incompleteness of their analysis. And you talk about cherry picking? I attempted to post there and was summarily rejected.

        The issue as of late concerning OHC increases and why it stopped after 2003 stems from this NPR article:
        http://www.npr.org/templates/story/story.php?storyId=88520025 where Kevin Trenberth to a higher degree than Josh Willis acknowledges there is a problem .

        Since April, Roger Pielke Sr. has had an ongoing discussion on his weblog with Josh Willis (co-author of Hansen et al 2005) on the issue of OHC from which updated OHC through 2007 is available. The Lyman paper is based on data through ~mid 2006.

        RPS challenged RC and received the same treatment anyone disagreeing with them gets. For you to say my questions would be laughed at by RC is irrelevant. The IPCC references Hansen et al 2005 in AR4 and is a cornerstone of CO2 AGW hypothesis. Ten years (1993-2003) of data was plenty long enough for OHC to be the “smoking gun” for AGW, yet it is now going on 5 years since with no warming but that is just noise?

        For those interested in the RPS weblog, go to http://climatesci.org/page/2/?s=ocean+heat+content&submit=Search and use ‘ocean heat content’ in the search window.

        • bender
          Posted Sep 18, 2008 at 10:52 AM | Permalink

          Re: DG (#155),

          If I wanted snarky replies, obfuscation and condescension RC does that well enough.

          Snark? Obfuscation? Why do you take what I wrote that way? It was brief, concise. I asked you an honest question. This is obfuscation? The question was not rhetorical. Perhaps you are a little cynical?

          You say “there is a problem”. RC discusses that at length, so I don’t see the disagreement there. Until they get the instrumentation working correctly I don’t quite know what to make of that data.

          How was I to know you’ve been researching the topic for 1.5 years? I was only offering a reference that I thought might be relevant. Lighten up.

  56. Francois Ouellette
    Posted Sep 17, 2008 at 10:37 AM | Permalink | Reply

    The claim that “we cannot predict next month’s weather in London, so how in the world can we predict the effect of human-made greenhouse gases in 50 years!” is a nonsensical statement, failing to recognize the difference between chaotic weather fluctuations and the deterministic response of the Earth to a large change in the planet’s energy balance.

    Surely Hansen knows that, by definition, chaos is the result of entirely deterministic systems, and that, conversely, entirely deterministic systems can be entirely unpredictable if they are chaotic. Now, chaos appears when you have nonlinearities in your system (and you don’t need much). What he seems to be saying is that the Earth responds “linearly” to a change in energy balance. But surely he knows (and says so when it’s convenient, eg. tipping points) that the Earth’s response is not linear, especially if we’re talking about a “large change in energy balance”. The whole glacial age thing is the proof that climate is atrociously nonlinear in its response: a small change in irradiation results in a large temperature change.

    So you can’t have it both ways: climate cannot be linear and predictable sometimes, and nonlinear and chaotic other times. You just can’t claim that the chaos disappears when “smoothed” over a long period of time. That is just NOT the definition of chaos. Think fractals: whatever the scale, they look the same.

    As for CO2 and glacial ages, maybe Hansen knows why CO2 was so low during the glaciation? Well, good for him then, because the experts in the field readily admit that they don’t have an explanation yet, and therefore miss an important piece of the puzzle that is the interaction of CO2 and the biosphere. Sure there are feedbacks and thresholds, but to claim that we understand, and better, that we have a “quantitative” knowledge of how they work is just not supported by the scientific literature, and is the object of no consensus at all.

    • bender
      Posted Sep 17, 2008 at 10:51 AM | Permalink | Reply

      Re: Francois Ouellette (#85),
      He displays a superficial understanding of the chaos problem. He assumes it is operating at hourly, daily, weekly, monthly time-scales, but not decadal or secular. These folks appear to be in denial over the real, statistical problem of LTP.

    • bender
      Posted Sep 17, 2008 at 10:56 AM | Permalink | Reply

      Re: Francois Ouellette (#85),

      Think fractals: whatever the scale, they look the same.

      Francois, I think it is an open question. One that is being addressed on the Mandelbrot thread. Hansen seems to have an undergraduate’s understanding of the chaos problem. The clean division of time scales between “weather” and “climate” that is presumed by so many in the field, but explicitly stated by none.

  57. Demesure
    Posted Sep 17, 2008 at 10:56 AM | Permalink | Reply

    IF there is WARMING IN THE PIPELINE, as you assume, WHERE IS IT, hiding in molecules in an unknown quantum state????

    Re: kuhnkat (#21),
    Yeah, it reminds me of a discussion some 6 months ago with an AGWer about another Hansen’s paper. I pointed out that Hansen has been explaining the past 6 year non-warming in the extra heat stored in the oceans “pipeline”. But with the Argos array showing oceans cooling (see Josh Willis), his argument is being destroyed. And the guy concurred with me saying he found disappointing that Hansen failed to mention in his paper that discrepancy.
    snip

    • bender
      Posted Sep 17, 2008 at 11:08 AM | Permalink | Reply

      Re: Demesure (#89),

      This Josh Wilis?

      Correction to “Recent Cooling of the Upper Ocean”

      Abstract. Two systematic biases have been discovered in the ocean temperature data used by Lyman et al. [2006]. These biases are both substantially larger than sampling errors estimated in Lyman et al. [2006], and appear to be the cause of the rapid cooling reported in that work.

      • Demesure
        Posted Sep 17, 2008 at 11:38 AM | Permalink | Reply

        Re: bender (#90),
        No bender, that Willis Josh (must be a cousin ;) )

        In fact, “there has been a very slight cooling,” according to a U.S. National Public Radio (NPR) interview with Josh Willis at NASA’s Jet Propulsion Laboratory, a scientist who keeps close watch on the Argo findings.

  58. tty
    Posted Sep 17, 2008 at 12:04 PM | Permalink | Reply

    Re 72

    That the last ice age (MIS 2-4) was especially cold is a claim you see fairly often, but the evidence for it is weak. It seems clear that the next-to-last glaciation (MIS 6) and the fifth back (MIS 12) were both considerably larger, measured in ice extent, and probably colder too (MIS 12 may have been the biggest and coldest of all).

    What is clear is that about 800,000 years ago, at the beginning of the Middle Pleistocene, there was a shift from a 41 kyr (kiloyear) to 100 kyr glacial cycle, and that the amplitude of the cycles also increased greatly. Interestingly the amplitude increased in both directions. The glaciations from MIS 16 onwards have been much colder, and the interglacials from MIS 11 have been much warmer than during the previous 2 million years. The previous interglacial MIS 5e was probably the warmest preiod for about 2 million years, but the current one is also quite warm, probably warmer than about 97% of the last million year.
    Whether this change in cyclicity means that Earth is heading into still colder climates, or on its way out of this glacial period, I don’t know. It does seem that the long-term cooling trend underlying the glacial/interglacial cycling flattened out at about the time that the 41-to-100 kyr shift occurred.
    Incidentally Dr Hansen’s claim that “a single CFC factory” is enough to eliminate the effect of Milankovich cycling, which has modulated climate for at least the last 250 million years seems rather hubristic.

  59. bender
    Posted Sep 17, 2008 at 12:06 PM | Permalink | Reply

    So the cooling that was considered “rapid” in 2006 is now considered “very slight” in 2008? Sounds like another case of “we don’t know yet, we’re actually still trying to sort it all out”.

    • Pat Keating
      Posted Sep 17, 2008 at 12:36 PM | Permalink | Reply

      Re: bender (#93),

      It’s analogous to the position on upper-troposphere cooling. If the data doesn’t agree with the models, then the data must be wrong.

      • bender
        Posted Sep 17, 2008 at 12:48 PM | Permalink | Reply

        Re: Pat Keating (#96),
        No, it’s not. Because the warming trend pre 2003 exists either way, and is quite robust. The alleged lack of ocean warming since 2003 is about as mysterious as the lack of surface warming since 2001. The GCMs suggest these deviations can happen over short time intervals of a few years. I too wish data didn’t need to be “corrected”. But as these systems were designed to measure weather, not climate, they are inherently dodgy. That’s why I am far more convinced by a 40-year trend that is robust to any kind of correction vs. a 5-year deviation from a trend that goes up or down depending on how correction is carried out.

        • Pat Keating
          Posted Sep 17, 2008 at 1:41 PM | Permalink

          Re: bender (#97),
          If the instrumentation isn’t up to the task then it is a waste of time to build theoretical structures until there is instrumentation that is. Correction of bad data is GIGO unless the correction is extremely well-founded.

        • bender
          Posted Sep 17, 2008 at 1:50 PM | Permalink

          Re: Pat Keating (#105),
          I can’t disagree, Pat. I am unqualified to judge the quality of the source data. I reluctantly accept it with an unhealthy mix of faith and skepticism, hoping for something more robust in the near future.

        • ianl
          Posted Sep 17, 2008 at 4:35 PM | Permalink

          Re: bender (#97),
          Bender

          And why have you picked a “40 year” time grab, please ?

          The arbitrariness of AGW pea&thimble time slices is a constant source of irritation.

        • bender
          Posted Sep 17, 2008 at 4:39 PM | Permalink

          Re: ianl (#120),

          And why have you picked a “40 year” time grab, please ?

          That’s the full length of the data series.

          The arbitrariness of AGW pea&thimble time slices is a constant source of irritation.

          That happens equally on both sides, friend.

        • bender
          Posted Sep 17, 2008 at 4:48 PM | Permalink

          Re: ianl (#120),
          Actually, you have something of a point here. I picked the number 40 because it was round, just to make a very quick point. But as I look over #94 more carefully I see the data start in 1951. And whether you choose 1951 (53 years of data) or 1964 (40 years of data) makes a significant difference in terms of esimated slope. Thank you for prompting me to be a little more precise.

        • bender
          Posted Sep 17, 2008 at 4:50 PM | Permalink

          Re: bender (#123),
          … but it doesn’t change my comment any, as both slopes are significantly positive.

        • ianl
          Posted Sep 17, 2008 at 10:25 PM | Permalink

          Re: bender (#124),

          Bender

          Bluntly, you’re not the only one to do that.

          My point is that AGW time grabs arbitrarily move about according to whichever cherry-pick they may want at the time.

          My own view is that from 1979 (about 30 years now) to now is one good time slice as that’s when satellite measurements were introduced. For the century or so previous to that, we have individual and sparsely-spread thermometers, ship buckets etc

          Before that we have Mannian third-order proxies and anecdotal evidence in the form of paintings, written descriptions and the like. Reliably splicing this data together is the Mannian bane of life. For example, in 1066 Billy the Kid (aka William the Conqueror) landed his invading fleet on an English shore that has now retreated many kilometres east of his landing point (attested historical fact). This says outright that sea levels (and so temperatures) were higher than today.

          Time slices matter a great deal, so pea&thimble variants of these are not helpful.

        • bender
          Posted Sep 17, 2008 at 10:34 PM | Permalink

          Re: ianl (#142),

          Time slices matter a great deal

          Yes, I could not agree more! That’s why I went back and clarified, to help prove your point.

          Re: DeWitt Payne (#141),
          Did I agree to that? Call it what you like.

        • Posted Sep 18, 2008 at 2:00 AM | Permalink

          Re: ianl (#142),

          My point precisely re Billy the Kid but that would be considered anecdotal. If you would like to repeat your comment with any references in my new thread ‘Have we been this way before’ I would be greatful/ I am trying to locate firm evidence of an audited quality to counter such claims that current sea levels or temperatures are unique in mans history. Hope this isnt off topic Steve.

          Tony Brown

        • bender
          Posted Sep 17, 2008 at 4:52 PM | Permalink

          Re: bender (#123), Hmm. Moreover RC’s trend analysis (referred to in #94) does NOT actually cover the full length of the data. And I had not noticed that!

  60. EW
    Posted Sep 17, 2008 at 12:32 PM | Permalink | Reply

    re 93
    Anyway, oceans do not seem to be warming. Otherwise there would be much rejoicing about confirmed AGW theories.

    • bender
      Posted Sep 17, 2008 at 12:54 PM | Permalink | Reply

      Re: EW (#95),

      oceans do not seem to be warming

      note the unfortunate, for you, crosspost with #94

      • Mark T.
        Posted Sep 17, 2008 at 1:14 PM | Permalink | Reply

        Re: bender (#99),

        note the unfortunate, for you, crosspost with #94

        While I cannot say I have read the entire paper (no access), from the abstract it seems to only go UP TO 2003, so none of the posts you’ve criticized are necessarily at odds with what is contained within that paper. Not that I know one way or another, just thought you might be a bit misplaced in your criticism.

        Mark

        • bender
          Posted Sep 17, 2008 at 1:29 PM | Permalink

          Re: Mark T. (#101),
          You think I don’t pay attention to the timescale? Re-read #97.

        • Mark T.
          Posted Sep 17, 2008 at 2:17 PM | Permalink

          Re: bender (#102),

          You think I don’t pay attention to the timescale? Re-read #97.

          Sorry, bender, I had not seen that post, but neither of their comments are specifically at odds with the paper you referenced, which was really all I was saying, i.e., the paper does not make their “cooling” assertions incorrect. Now, that these guys have a long way to go before the “trend” from 2003 or 2001 is meaningful is something I’m not debating.

          Mark

        • bender
          Posted Sep 17, 2008 at 2:26 PM | Permalink

          Re: Mark T. (#112),
          Then we’re on the same page.

  61. anna v
    Posted Sep 17, 2008 at 12:49 PM | Permalink | Reply

    It is instructive to look at the only map of CO2 available to us. Supposedly very soon we will get updated ones, after a thread in Anthony Watt’s blog.

    http://www-airs.jpl.nasa.gov/Products/CarbonDioxide/

    and at the current sea and ocean temperatures

    http://weather.unisys.com/surface/sst.html

    July is not so far off from September.

    So is CO2 heating the seas? CO2 whose back radiation can penetrate only a few mm of the sea surface? All those 138/100000 antropogenic extra molecules of it? From the distribution it looks to me more like the hard radiation from the sun that is doing it, which penetrates meters in the water.

    Empirically, if the night is cloudy, the sea stays warm. If the night is clear it is colder in the morning than in the afternoon.

    Just some real data.

  62. UK John
    Posted Sep 17, 2008 at 1:37 PM | Permalink | Reply

    Ocean warming over the last 40 years according to instrumental records, that is all that appears to be available. Before then ? who knows !

    I found this quite clear.

    http://hadobs.metoffice.com/hadgoa/RAPID07_Palmer_et_al_poster.pdf

    • bender
      Posted Sep 17, 2008 at 1:47 PM | Permalink | Reply

      Re: UK John (#104),
      It is an unfortunate paradox that short-term cooling is not inconsistent with long-term warming. Especially if the short-term stuff is chaos or noise, and the long-term stuff is the deterrministic response referred to by Hansen.

      Unfortunately, anyone wanting to unequivocally claim that “the earth is cooling” is going to have to battle me on the statistics of trend analysis and the details of the ocean and land surface data.

      One wonders how much A+O heat was lost to space in the 1997/98 El Nino. This is the sort of thing that could linger on for years given the slow response time of the oceans. Is that why current temps are flatlining? If so, watch for a rise just as soon as the “global cooling” rhetoric hits a fevered pitch.

      But the topic is testimony. I want to highlight Hansen’s absurdly simple model of climate noise.

  63. Craig Loehle
    Posted Sep 17, 2008 at 1:53 PM | Permalink | Reply

    Re: Hansen’s assertions about extinctions. In the following paper, some very distinguished scientists came together in an anti-consensus that alarming statements about future extinction rates (including Hansen’s testimony) are simply not supported by science.
    Daniel B. Botkin, Henrik Saxe, Miguel B. Araújo, Richard Betts, Richard Bradshaw, Tomas Cedhagen, Peter Chesson, Margaret B. Davis, Terry Dawson, Julie Etterson, Daniel P. Faith, Simon Ferrier, Antoine Guisan, Anja Skjoldborg Hansen, David Hilbert, Peter Kareiva, Craig Loehle, Chris Margules, Mark New, Flemming Skov, Matthew J. Sobel, David Stockwell, and Jens-Christian Svenning. 2007. Forecasting Effects of Global Warming on Biodiversity. Bioscience 57:227-236.

    • bender
      Posted Sep 17, 2008 at 2:12 PM | Permalink | Reply

      Re: Craig Loehle (#108),
      From the abstract:

      While current empirical and theoretical ecological results suggest that many species could be at risk from global warming, during the recent ice ages surprisingly few species became extinct.

  64. Craig Loehle
    Posted Sep 17, 2008 at 1:58 PM | Permalink | Reply

    On the cause of ice ages: about 2 million years ago, North & South America joined up (which caused lots of extinctions in SA as predators moved south) at Panama. This altered ocean currents by separating Atlantic & Pacific and contributed to the past 2 Million years of ice ages being worse than before. It is certainly not all about CO2. In science it is rarely the case that single causes explain something, much less everything.

    • bender
      Posted Sep 17, 2008 at 2:07 PM | Permalink | Reply

      Re: Craig Loehle (#109),

      In science it is rarely the case that single causes explain something, much less everything.

      This is the tyranny of the law of parsimony. In natural systems Occam’s razor slices and dices everything in sight. Nice paper, Dr. Loehle.

  65. Max
    Posted Sep 17, 2008 at 2:49 PM | Permalink | Reply

    Question: I am still not feeling satisfied by Mr. Hansens explanation:

    – GHGs can work both as forcing and as feedback, the notion is clear, also that water vapour is a positive feedback effect
    – When water warms the amount of water vapour will increase, as will C02

    So, this is meant with positive feedback, but we had many such events during the earth climate history and some swings in temperature were even higher. So, what negative feedback brought the whole thing back? This whole chapter about forcings doesn’t add up?
    Let’s take an example:

    – Solar Irradiance changes (let’s say about 2% and more)
    – Now, world heats up temperature rises, ocean releases CO2 and water vapor as it warms (even with lag)
    – Temperature rise even father, CO2 and water vapour are released until a natural balance limit is reached (otherwise you could “over-satisfy” the athmosphere)

    then what? If climate change is mostly positive feedback, what has brought it back in the past and why isn’t it factored in today? I mean, yes, ice sheets can cool until they are gone (see figure 1), but there was a period before, where no ice sheets were presented, and the climate still came around.

    I don’t actually buy the idea that a change in the time scale (centuries instead of millenia) proves such a big difference, because water temperature lags (as clearly stated) and full-response is even slower. So, if one feedback/force has a high rate of change, it doesn’t mean that all the other feedbacks are still slow in response (for example high delta_T of water results in higher rate of heating!).
    Also, I don’t buy the danger of it, if he states that water levels can be 75 meters higher (and the whole climate still came around), meaning this are 75 meters of possible cooling volume, that is not yet used.
    So, was it (for the old climate periods) always the cyclic change of the sun that brought the climate around?

    • Pat Keating
      Posted Sep 17, 2008 at 3:12 PM | Permalink | Reply

      Re: Max (#114),

      water vapour is a positive feedback effect….this is meant with positive feedback, but we had many such events during the earth climate history and some swings in temperature were even higher. So, what negative feedback brought the whole thing back?

      If water-vapor provides positive feedback at low absolute-humidity levels and negative feedback at high humidity levels, you have an explanation. The results obtained by Curry and colleagues in polar regions and Lindzen et al in the tropics suggest just that.

  66. Posted Sep 17, 2008 at 3:48 PM | Permalink | Reply

    The day following the judgement a spokeperson for Greenpeace was speaking on BBC radio citing ‘facts and figures’. He sounded surprised by their victory but as full viondication for their actions he cited ‘the recent Pierie report.’

    I assume that in here are lots of other ‘science’ based information that is being used as a handbook by green organisations. However I can find no trace of it.

    That might mean that either;
    a) It does not exist
    b) Far more likely, I misheard. Ir was early and I was only half listening.

    If anyone can identify the report it might throw up some further data that Hansen and others might have had a hand in

    Tony Brown

    • Posted Sep 17, 2008 at 4:58 PM | Permalink | Reply

      Re: Tony Brown (#118),

      My #118 Perhaps the reference was to Guy Pearse? He seems to have been involved with Hansen on the Garnaut review in Australia

      I hadn’t realised Hansen was quite so political (there I was thinking he was merely a Nasa climate scientist) and seems to pop up everywhere. He seems to have been much more equivocal in his paper Target CO2: Where Should Humanity Aim?, which I guess was suitably dissected at CA.

      In the following extract there seems to be an acceptance we should do something about other forcings, an apparent acceptance that we have decades in which to act rather than just today, and his use of unlikely’ rather than ‘definite’ seems more moderate than his Kingsnorth testimony.

      Extract
      ‘We suggest an initial objective of reducing atmospheric CO2 to 350 ppm, with the target to be adjusted as scientific understanding and empirical evidence of climate effects accumulate. Limited opportunities for reduction of non-CO2 human-caused forcings are important to pursue but do not alter the initial 350 ppm
      CO2 target. This target must be pursued on a timescale of decades, as paleoclimate and ongoing changes, and the ocean response time, suggest that it would be foolhardy to allow CO2 to stay in the dangerous zone for centuries. A practical global strategy almost surely requires a rising global price on CO2 emissions and phase-out of coal use except for cases where the CO2 is captured and sequestered. The carbon price should eliminate use of unconventional fossil fuels, unless, as is unlikely, the CO2 can be
      captured. A reward system for improved agricultural and forestry practices that sequester carbon could remove the
      current CO2 overshoot. With simultaneous policies to reduce non-CO2 greenhouse gases, it appears still feasible to avert catastrophic climate change. Present policies, with continued construction of coal-fired power plants without CO2 capture, suggest that decision-makers do not appreciate the gravity of the situation. We must begin to move now toward the era beyond fossil fuels. Continued growth of greenhouse gas emissions, for just another decade, practically eliminates the possibility of near-term
      return of atmospheric composition beneath the tipping level for catastrophic effects.
      The most difficult task, phase-out over the next 20-25 years of coal use that does not capture CO2, is herculean, yet feasible when compared with the efforts that went into World War II. The stakes, for all life on the planet, surpass those of any previous crisis. The greatest danger is continued ignorance and denial,which could make tragic consequences unavoidable.’

      (this extract from http://www.getup.org.au)

      Hope this isn’t off topic but I thought it gave amplification to Hansens testimony and perhaps pinpoints Greenpeaces reliance on Hansen and Pearse. I still don’t know what the Pearse report is though!

      Tony Brown

      • Geoff Sherrington
        Posted Sep 18, 2008 at 3:24 AM | Permalink | Reply

        Re: Tony Brown (#126),
        Tony Brown, With a word search through the last 2 Australian Garnaut reports I was unable to find a Pearse or similar. The closest Australian I can imagine, and this is no more than a guess, not meant to implicate him, is Graeme Pearson. For flavour, in 2005 he attended Melbourne University’s Australian Student Environment Network, who reported in their newsletter

        Green Week, an environment themed week within the Union, was held between 8-14 August and was a great success. Events included a talk on climate change by Dr Graham Pearson, former chief atmospheric scientist for CSIRO, a free breakfast for students who traveled to campus via sustainable transport, a cake stall fundraiser, the VSU National Day of Action and a tree planting weekend to help restore breeding habitat for the Regent Honeyeater.

        The Climate Change Collective held a social night to engage more students in the campaign against climate change on campus. Michelle Braunstein from Friends of the Earth gave a talk about climate refugees, which was followed by a delicious dinner and a climate change trivia night. Much fun was had by all. The Climate Change Collective is also currently working on a proposal to submit to key decision makers within the university administration calling for significant improvement in the University of Melbourne’s energy practices

        I noticed the discussion of climate refugees was followed by a delicious dinner. But this is well OT .

        • kim
          Posted Sep 18, 2008 at 4:42 AM | Permalink

          Re: Geoff Sherrington (#149),

          No worries, Geoff; seeing the difficulties ahead realistically is a lot better than imagining non existent ones or exaggerating small ones. Per Asperum Ad Astra.
          ============================================

  67. bender
    Posted Sep 17, 2008 at 4:41 PM | Permalink | Reply

    But I agree: it’s a problem.

  68. ImranCan
    Posted Sep 17, 2008 at 6:11 PM | Permalink | Reply

    Looking at Hansens testimony document one can see the graph showing he beautiful correlation between CO2 and temperature – albeit with a few centuries of offset. There is then a lot of discussion about dependency – leading vs. lagging, GHG feedback etc. And many statements that either directly or though implication suggest CO2 is the primary controller of temperature. Is it not possible to demonstrate through mathematics that the only way to get such good correlation is to have 1 variable fully dependant on the other – with no reverse or limted reverse influence ??

    There again, I’m only a truck driver – what do I know?

  69. John S.
    Posted Sep 17, 2008 at 6:28 PM | Permalink | Reply

    The most astonishing–and least noticed–thing about Hansen’s testimony is recourse to concepts of system behavior that are wholly unscientific. The inescapable physical fact is that the climate system is entirely passive without internal energy-producing mechanisms. The only external forcing is insolation. By system science definition, feedback is not an intensifying or diminishing system response characteristic, but a looping back of the output signal to change the input. Natural systems cannot have true positive feedback, for that would imply that energy is being produced by the system. Nothing changes TOA insolation, greenhouse is simply a capacitance effect, and all the fashionable talk of various imputed greenhouse “forcings” and “feedbacks” cannot be made conceptually cogent, let alone physically persuasive. All such claims should be challenged analytically.

    • bender
      Posted Sep 17, 2008 at 6:32 PM | Permalink | Reply

      Re: John S. (#130), Nonsense. If the presence of X favors the production of more X, this is a positive feedback, regardless of the physical system.

      • John S.
        Posted Sep 17, 2008 at 8:46 PM | Permalink | Reply

        Re: bender (#131)
        X favoring–in some unspecified sense–more X may be “positive feedback” in your lexicon, but that is not the scientific one. Instead of merely offering obiter dicta, why don’t you try to show rigorously how true positive feedback (beyond mere recirculation) can be obtained without an additional energy source. You’ll find that you’re confusing feedback with nonlinear response characteristic, such as a snowball growing as it rolls downslope–until it runs out of slope.

        • bender
          Posted Sep 17, 2008 at 9:07 PM | Permalink

          Re: John S. (#135),
          C’mon John S, this is not rocket science. X = atmospheric CO2. The positive feedback doesn’t serve to create energy from nothing. It serves to concentrate CO2 in the atmosphere, where it is more active than in lithosphere or hydrosphere. And it is not a direct feedback. It is indirect. It is the indirectness that creates the lag, leading to the concepts of slow vs. fast feedbacks.

          If you think this kind of “feedback” is purely a heuristic device, and not “true” feedback, so be it. You argument is semantic and therefore irrelevant.

        • bender
          Posted Sep 17, 2008 at 9:19 PM | Permalink

          Re: John S. (#135),
          Confuesd, I am not. X causes Y causes X. This is a “feedback” in the conventional sense of term. X feeds back onto X. That there is indirection and delay makes it a particular kind of feedback, but it is feedback.

        • DeWitt Payne
          Posted Sep 17, 2008 at 10:12 PM | Permalink

          Re: bender (#140),

          I thought we decided a while back that more or less gain was a better term than positive or negative feedback.

        • Mark T
          Posted Sep 17, 2008 at 11:16 PM | Permalink

          Re: DeWitt Payne (#141),

          I thought we decided a while back that more or less gain was a better term than positive or negative feedback.

          Uh, you can decide that, but they mean completely different things.

          Mark

  70. Soronel Haetir
    Posted Sep 17, 2008 at 6:36 PM | Permalink | Reply

    On a tangent, would Hansen’s work be considered robust enough to survive a Daubert challenge if this were tried in the US? (Not that I would expect such a defense to be allowed under US law)

  71. Jaye
    Posted Sep 17, 2008 at 6:40 PM | Permalink | Reply

    Noticed a few posts concerning a system being both deterministic and chaotic. That is possible for certain types of functions, iterated function systems…see “Fractals Everywhere” by Michael Barnsley. Also something like f(x) = lambda*x(1-x) can be both deterministic and chaotic depending on the value of lambda…form doesn’t change but the coefficients can “tip” it from orderly to chaotic.

  72. wmanny
    Posted Sep 17, 2008 at 8:15 PM | Permalink | Reply

    Snippable commentary, perhaps, but this document, taken as a whole, does not read as testimony nearly so well as it reads as a B-movie script. Astoundingly irresponsible sci-fi.

  73. Kenneth Fritsch
    Posted Sep 17, 2008 at 8:51 PM | Permalink | Reply

    Hansen’s Kingsnorth testimony was another instance of what I have observed as the IPCC approach to the story on AGW, i.e providing the evidence for one side without rebuttal from the other. I went back to the Greenpeace coverage of the trial and as it turns out the other side, the prosecution in this case, only argued the legal issues of destroying property to save property and when it is lawful and when it is not.

    So here we have Hansen, a scientist, presenting evidence for the detrimental effects of global warming in a court of law where one expects the testimony to show only one side at a time because the other side will show there one-sided evidence also. That was not the case here, and thus Hansen can afford himself the liberties of presenting his case as a defense lawyer if you will and with no scientific rebuttal.

    To that end Hansen, did an excellent job and I think without presenting anything that he has not said elsewhere. That he had footnotes to references is not much different than the one-sided reviews that the IPCC provides. He covers so many points of AGW that one interested in a reply would need to do a detailed analysis of his referenced papers. That Hansen can string together all the facts and conjectures to show that the effects of AGW need be all detrimental is no mean accomplishment. But the fact that they all turn out bad makes the case appear more suited for an adversarial trial than a scientific statement.

    I was a little confused about Hansen’s remarks that ice ages have been permanently mitigated with the GHG emission from man to date. That seems like a good thing, but I was unclear how we were going to maintain that happy equilibrium which I guess means maintaining conditions just as they are today or at least in modern times- another coincidence that we have the optimum conditions right now.

    • bender
      Posted Sep 17, 2008 at 9:10 PM | Permalink | Reply

      Re: Kenneth Fritsch (#136),

      without presenting anything that he has not said elsewhere

      Ken, what about tectonic forcings via vulcanism (+) and weathering (-), and the CO2 (+) feedbacks they initiate? Where is that stuff located in the literature and in AR4?

      • Kenneth Fritsch
        Posted Sep 18, 2008 at 9:07 AM | Permalink | Reply

        Re: bender (#138),

        I did not bother to look at Hansen’s references but the fact that scientists have looked at the issues you noted I have no doubt. My point was that the IPCC and Hansen at trial with no cross examination on the evidence that they bring to table is not very scientific no matter the number of references they can produce.

        The links below address (a) the weathering from the uprising Appalachian Mountains and an ice age 450 million years ago, (b) scientists suspecting that our current ice age, which began 40 million years ago, was caused by the rise of the Himalayas and (c) a mechanism for CO2 recycling from subduction zones:

        http://researchnews.osu.edu/archive/wethring.htm

        http://www.geosociety.org/meetings/2006/pr/wethring_GSAformat.pdf

        http://www.nature.com/nature/journal/v357/n6379/abs/357578a0.html

        http://petrology.oxfordjournals.org/cgi/content/full/45/6/1089

      • Kenneth Fritsch
        Posted Sep 19, 2008 at 8:34 PM | Permalink | Reply

        Re: bender (#138),

        Ken, what about tectonic forcings via vulcanism (+) and weathering (-), and the CO2 (+) feedbacks they initiate? Where is that stuff located in the literature and in AR4?

        Re: bender (#192),

        IPCC AR4:

        Changes in CO2 on these long time scales are thought to be driven by changes in tectonic processes (e.g., volcanic activity source and silicate weathering drawdown; e.g., Ruddiman, 1997).
        Ruddiman, W.F. (ed.), 1997: Tectonic Uplift and Climate Change. Plenum Press, New York, 535 pp.

        [India collision with Asia preventing runaway warming in PETM?]

        OK when can commence talking about the newer issues proposed in Hansen testimony, i.e silicate weathering of uplifted mountains?

        Do we have geologists ready in the wings to tell us how close mountain uplifting corresponds to glacial periods in geological times and precisions? What are back of the envelop calculations for CO2 reactions with silcates given a CO2 partial pressure? What are the kinetics of the reactions? How well do the strontium isotope ratios fit the theories (of riverine deposits??) and how accurately can they be measured? What are the countervailing theories – if any?

        • DeWitt Payne
          Posted Sep 20, 2008 at 12:36 AM | Permalink

          Re: Kenneth Fritsch (#196),

          You could start with the review article by M.E.Raymo & W.F.Ruddiman, Tectonic forcing of late Cenozoic climate, Nature, Vol 359, 10 September 1992, pp 117-122. I think they were the ones who first proposed the uplift of the Tibetan plateau as the cause of the reduction of CO2 to current levels. There are lots of caveats in the review article though. For one thing, there has to be some other mechanism(s) to maintain CO2 or increased weathering would strip all CO2 from the atmosphere in a few million years.

          Strontium isotope ratios can be measured at the delta ppm level using a medium to high resolution magnetic sector mass spectrometer with multiple fixed collectors and either thermal ionization or inductively coupled plasma as an ion source.

    • bender
      Posted Sep 17, 2008 at 9:12 PM | Permalink | Reply

      Re: Kenneth Fritsch (#136),

      I was unclear how we were going to maintain that happy equilibrium

      What I took from this is that there is NO happy equilibrium. Rather, you have a choice of hothouse or icehouse, and no way to get the system to lock on to something intermediately pleasant.

  74. Nicholas
    Posted Sep 17, 2008 at 11:42 PM | Permalink | Reply

    (I hope this isn’t too off-topic, maybe we should take this discussion to unthreaded? I’m sure it relates to Hansen’s testimony but in a tangential way.)

    DeWitt, Mark T., I think it’s a matter of semantics. Observe:

    A system with a single positive feedback mechanism, or with multiple feedbacks all positive, always leads to instability and the system will go to one extreme and stay there. Even a tiny bit of positive feedback will result in this.

    A system with a single negative feedback mechanism, or with multiple feedbacks all negative, always leads to stability, and you can quantify the “gain” of the system based on the amount of negative feedback.

    A system with multiple feedbacks of mixed sign may be inherently stable, or may (likely will) have regions of instability. In some regions, you will have relatively stable gain on your inputs (forcings), and it may be less than or greater than one. If it’s less than one, a forcing of x will lead to an ultimate change of less than x. If it’s greater than one, a forcing of x will lead to an ultimate change of greater than x. There may be a point where a system crosses over from gain of less than one to greater than one as one feedback starts dominating over another. Gain can also depend on frequency, i.e. how rapidly the forcings (or the state of the system) change, not just on the magnitude of the forcings at any particular instant.

    This is all based on feedbacks in electronic circuits but I think the same concept extends to climate without modification, the only real difference really is the complexity of the system.

    So I would agree that talking about whether the gain is less than or greater than one makes more sense. In reality what you are talking about the relative magnitude of the positive and negative feedbacks which are interacting. However, it may also be useful to talk about the sign of a particular feedback, but chances are there are always going to be multiple feedbacks in effect at any given time. To say that the gain is less than one in a given regime is to say that the negative feedbacks are dominating. So really both make sense with the correct frame of reference.

  75. Nicholas
    Posted Sep 17, 2008 at 11:49 PM | Permalink | Reply

    Actually I’m sorry, that isn’t right. A positive feedback with a gain less than 1 doesn’t necessarily lead to instability, just amplifications. So, I think both sign and magnitude are important when discussing feedbacks…

    I think my comments about how they interact still apply, though.

  76. Geoff Sherrington
    Posted Sep 18, 2008 at 4:36 AM | Permalink | Reply

    This Hansen statement is factually incorrect in at least 3 places. (I have found about a dozen other errors elsewhere).

    Fig. 5b shows that if coal CO2 emissions were phased out over 2010-2030, atmospheric CO2 would peak at 400-425 ppm. In that case it would just be feasible to get atmospheric CO2 back beneath 350 ppm via the carbon uptake potential of improved forestry and agricultural practices, which could draw down atmospheric CO2 by as much as about 50 ppm. If it turns out that actual oil and gas reserves are toward the higher end of the estimated range, then it may be necessary to capture and sequester CO2 at some of the gas-fired power plants, or to burn appropriate biofuels (not food crops) at power plants that capture and sequester CO2.

    First, it is incorrect because of a misunderstanding of botanical products in the carbon cycle. As a good approximation, all dead botanical matter including trees breaks down to produce CO2. Some processes are rapid (minutes) some take centuries, but they all get to be CO2 unless the biomass is converted to coal or peat, or buried in small amounts as soils with debris to form sediments. These are not major process in the last 10,000 years, so far as I know.

    Therefore, greater sequestration of carbon by vegetation, in a practical or managed sense, involves an increase in the product of vegetation weight and carbon content per unit area of land. Proposals such as that above, to burn biomass instead of coal or oil, have no meaning. The cyclic turnover rate of CO2 might be altered, but the sequestration can change and so have a climate influence only if the mass of bound carbon is increased – and here is the rub – not just for the life of a plantation of new trees, but forever.

    Unless subbtle, unstated factors are involved, an emission trading scheme that rewards people who plant trees will work only if the trees eventually accumulate more carbon than before – and are kept at that size or better forever.

    Of course, this leads to an anti-scam proposal similar to the McKitrick T3 tax. Those gaining from emission imposts by planting trees should be rewarded according to the (annual?) estimate of the change in sequestered carbon mass/area. If they walk away with pockets stuffed with cash and the trees die, the money should be repaid. It’s called “reward for effort” rather than “unearned income”.

    The second and major error is that coal CO2 emissions cannot be phased out over 2010-2030 in the economic structures of today. At best, to increase the present rate of progress, some oil could replace some coal (if coal is the demon and sequestration of its CO2 remains unproven), but oil gives CO2 as well. Nuclear plants cannot be approved and built fast enough. Wind farms and solar require backup power almost as large as their own output and the backup is usually of the more expensive type for fast peak switching. Because the proposition is a physical and economic impossibility, one wonders why it was raised at all. Even school children should see through this one.

    Finally, land agricultural changes on a large scale affect surface albedo and probably local climate like humidity in ways that need corect accounting and auditing, plus good Global Climate Models. Oh dear.

    • Pat Keating
      Posted Sep 18, 2008 at 3:36 PM | Permalink | Reply

      Re: Geoff Sherrington (#150),

      Actually, if you really were worried about CO2, the important thing would be to drag out the fallen trees and large branches and use those to heat our homes etc. It is the dead trees that ‘de-sequester’ the carbon, so the folks with wood-burning stoves are the heroes.

      • Geoff Sherrington
        Posted Sep 19, 2008 at 4:01 AM | Permalink | Reply

        Re: Pat Keating (#167),

        Pat, you jest. Dead wood gives off CO2 whether you burn it or let it decay. Though the dynamics might be different, in the long term the balance is much the same.

        • Pat Keating
          Posted Sep 19, 2008 at 8:20 AM | Permalink

          Re: Geoff Sherrington (#174),
          Of course it does, but you are missing the point.
          The dead wood is going to end up as CO2 either way, right? If we use it to heat our houses, that is less carbon we have to take out of the ground, right?
          If we let it rot in the woods, we are losing the useful energy it contains — only the termites get that energy and, to me, that is a waste.

        • Geoff Sherrington
          Posted Sep 20, 2008 at 1:49 AM | Permalink

          Re: Pat Keating (#176),

          Pat, I was assuming the Golden Dawn had happened and that the world was in the state described by Hansen, burning no more coal as in the report above –

          Coal, specifically prompt phase-out of coal emissions, is the one critical element in solution of the global warming problem, in preservation of a planet resembling the one on which civilization developed.

  77. Mango
    Posted Sep 18, 2008 at 5:46 AM | Permalink | Reply

    Does anybody know if Hansen was cross-examined or was he just allowed to read out his carefully prepared statement without cross-examination by the prosecutor? (I realise the crown prosecution were going for a verdict based on the criminal damage only)

  78. Steve McIntyre
    Posted Sep 18, 2008 at 8:02 AM | Permalink | Reply

    I’d be interested in a thread reporting on the talk.

    Deep Time events are really very interesting and I’d like to cover them more on the blog, particularly because they give an opportunity for geologists to contribute.

    What struck me in a very short consideration of the issue a couple of years ago was (!) that the theory was recent; (2) that Richard Alley was red-hot for it – that raised my antennae a little; (3) a Canadian geologist, Arnaud, at the U of Guelph had posited an alternate provenance for some of the evidence that did not involve a Snowball Earth. Arnaud:

    My PhD research focussed on the Neoproterozoic, a period in Earth history when some researchers believe glaciation was global, covering continents and oceans. The nature of Neoproterozoic environmental change in the North Atlantic region was reconstructed based on sedimentology and stratigraphy of rocks preserved in northern Norway and Scotland. Field work consisted of documenting the sedimentary characteristics of the glacigenic successions preserved in these two areas as well as mapping outcrop geometry and stratigraphic relationships of the various sediment types. This research specifically addressed the issue of distinguishing between climatic and tectonic controls on sedimentation and showed that it is sometimes difficult to infer the paleoclimatic significance of glacigenic deposits.

  79. EW
    Posted Sep 18, 2008 at 12:25 PM | Permalink | Reply

    #155 (DG)

    At Pielke’s site in the OHC discussions you mentioned, Willis presented recent values at this graph. Seems like still there’s nothing in the pipeline…

    • bender
      Posted Sep 18, 2008 at 12:38 PM | Permalink | Reply

      Re: EW (#158), Now that is interesting. What proportion of the ocean is sampled to produce a graph like that?

    • bender
      Posted Sep 18, 2008 at 12:43 PM | Permalink | Reply

      Re: EW (#158),
      Willis’s caveats are very important:

      Another thing that is important to note is that this excludes any warming in the deep ocean. Over four years, it is reasonable to expect at least some warming (or cooling) below 900 m as well as in regions that Argo does not sample such as under the sea ice.

      “OHC” is therefore not really OHC. The heating “in the pipe” is supposed to be exactly there – in the deep ocean and under sea ice. I think I’ll wait before concluding anything from these data.

      • bender
        Posted Sep 18, 2008 at 12:49 PM | Permalink | Reply

        Re: bender (#160),
        Pielke concurs:

        I agree with you on the deeper ocean. The only other explanation for continuing sea level rise is a rise in the ocean bottom on these time scales.

  80. John S.
    Posted Sep 18, 2008 at 12:48 PM | Permalink | Reply

    Bender (re: #137 & #140),

    Quite the contrary! With Hansen talking about “tipping points” in the climatic energy-budget, high priests of AGW raising the specter of “runaway greenhouse,” and modelers resorting to a fictitious positive water-vapor feedback in their calculations, energetics (power fluxes) in the geosystem is not only relevant, but the central issue. True feedback in any system concerns output power (or signal) flows back to the input (excitation). It is precisely at this point that the precious gem of daisy-chained illogic–“X causes Y causes X”–falls apart.

    For any physical system or component to cause anything, it must have energy. CO2, which you identify as X, produces not an iota of it. Like all greenhouse gases, it simply absorbs IR and re-radiates it omnidirectionally. It is not an “active” gas in any rigorous system-science sense, but merely a passive “slave” component, incapable of “forcing” or “triggering” anything by itself. Outgassing from the oceans makes its atmospheric concentration follow long-term global variations of temperature closely enough to inspire incredible surmises of causality, when viewing compressed time-histories from the Cenozoic onward. Miscomprehended and trivialized down to a point of patent confusion with simple gain by the analytically challenged, the concept of feedback has provided an au courant excuse for clinging to physically untenable concepts of power fluxes that are rampant among “climate scientists.”

    This is by no means the only instance of sloppy comprehension of terminology leading to physical misconceptions. No less astonishing is the prevalence of notion that the sluggish density-driven currents known as the “thermohaline circulation” are the main mechanism for oceanic heat redistribution. In reality, it’s the vastly more powerful wind-driven circulation that distributes equatorial heat poleward. And the conversion of solar power to mechanical energy for driving the winds, waves and currents thus remains neglected.

    • bender
      Posted Sep 18, 2008 at 12:51 PM | Permalink | Reply

      Re: John S. (#161),
      Semantics. So you think Hansen’s language is sloppy. So what?

  81. anna v
    Posted Sep 18, 2008 at 1:55 PM | Permalink | Reply

    bender:
    September 18th, 2008 at 12:43

    “OHC” is therefore not really OHC. The heating “in the pipe” is supposed to be exactly there – in the deep ocean and under sea ice. I think I’ll wait before concluding anything from these data.

    Hmmm. I find it very hard to think of a mechanis by which heat can be transferred to lower levels and under the ice if it does not affect the level studied. Conduction, convection, are the only ways I can think of. To heat the water, the metal kettle gets hot and transfers the heat to the water. I cannot see a way to keep the metal cooling and get heat to the water.

    • bender
      Posted Sep 19, 2008 at 11:34 AM | Permalink | Reply

      Re: anna v (#164),

      I find it very hard to think of a mechanis by which heat can be transferred to lower levels and under the ice if it does not affect the level studied. Conduction, convection, are the only ways I can think of. To heat the water, the metal kettle gets hot and transfers the heat to the water. I cannot see a way to keep the metal cooling and get heat to the water.

      Time delays in, say, the THC. The surface waters were warm. That warmth has since been subducted to the depths, out of the region where probes are currently located. A time delay is a reasonable proposition given what we know about the ocean’s time constant for deep mixing.

      But I am speculating. The point is that there is a shared burden of proof on those who want to conclude that the oceans are cooling to consider the whole ocean. That the surface temperatures are cooling now does not mean the depths are not warming.

  82. Michael Smith
    Posted Sep 18, 2008 at 2:29 PM | Permalink | Reply

    I have a question about Hansen’s 450 ppm “tipping point” for CO2. In his testimony, he said that he arrived at that figure because that was how far CO2 concentration had fallen during the Cenozoic before polar ice sheets appeared.

    However, at that time there were no anthropogenic aerosols. As I recall, IPCC AR4 calculated a net radiative forcing for aerosols of something like -1.2 W/m2. Isn’t the presence of these aerosols going to shift that CO2 tipping point upwards compared to what it was some 35 million years ago?

  83. Sam Urbinto
    Posted Sep 18, 2008 at 3:00 PM | Permalink | Reply

    Feedbacks. Positive ones move something away from equilibrium, either to a new one or continue to infinity or until the system breaks. Negative ones move something back towards equilibrium. Therefore, a substance that makes a system move to a new place (say -2) and then resists attempts to bring it away from -2 is both a positive and negative feedback depending on the part of the cycle one is looking at. The old is the bowl of this spoon convex or concave kind of thing.

    Pat Frank: 115

    If water-vapor provides positive feedback at low absolute-humidity levels and negative feedback at high humidity levels, you have an explanation. The results obtained by Curry and colleagues in polar regions and Lindzen et al in the tropics suggest just that.

    Given water vapor’s behavior as a short-lived not-well-mixed gas (and a minor radiative forcing in the stratosphere), that also participates in the hydrosphere, this seems obvious.

    • John S.
      Posted Sep 18, 2008 at 5:04 PM | Permalink | Reply

      Re: Sam Urbinto (#166), Can you give any example of a natural system with true positive feedback that moved to a “new equilibrium?”

  84. Urederra
    Posted Sep 18, 2008 at 4:23 PM | Permalink | Reply

    So, this guy was really awarded with a Nobel Peace Prize (since he is a contributing member of IPCC)?

  85. John S.
    Posted Sep 18, 2008 at 4:42 PM | Permalink | Reply

    Bender (re: #163),

    Get real! I was writing about clear comprehension of power flows in systems, not just sloppy semantics.

  86. bender
    Posted Sep 18, 2008 at 5:26 PM | Permalink | Reply

    Hi John S,
    My advice is to clarify your argument. It may not mean much to me right now, but that doesn’t mean it isn’t valuable. If you clarify it, you will probably reach a wider audience.

    • John S.
      Posted Sep 19, 2008 at 2:30 PM | Permalink | Reply

      Re: bender (#171), How much more basic do I need to get? I thought everyone in this august forum recognized that:

      1. The Earth and its atmosphere are surrounded by the vast heat sink of space and need constant replenishment of energy from the sun to maintain the gray-body and atmosperic brightness temperatures.

      2. Power fluxes (watts/sq.m) translate into temperatures via the Stefan-Boltzman law. If by modeling fiat you impute non-existent “positive feedbacks” into the calculations, then you wind up with unrealistic power fluxes. Thus Houghton, based on Trenbeth and accepted by IPCC, shows a flux of 519W/sq.m in the atmosphere, which translates into a brightness temperature ~34C for a global annual average, even higher than that of the surface. Does anyone here believe that?

      3. The commonly accepted range of figures ca. 3W/sq.m for the effect of doubling CO2 is merely a theoretical calculation based on capacity. The actual energy content of the additional CO2 would depend entirely upon presently unabsorbed energy in the 15-micron band. With that band nearly saturated even at 1930’s levels, there’s not much left to absorb. And as the very short time-constant of atmospheric temperature response to the diurnal cycle clearly shows, it’s not the atmosphere that provides the planetary temperature stability.

      4. No stability is possible in a system with net positive feedback. We can entertain vague notions of such (control engineers actual build some, but with operational amplifiers as a power source and hard output limiters to provide net stability), but nature does not produce any.

      5. No matter how vastly different the time constants of the atmosphere and ocean subsystem may be, they are incapable of any anticipatory action. Only causal sytems are physically realizable, and the difference between cause and effect should always be kept clearly in mind.

      • DeWitt Payne
        Posted Sep 19, 2008 at 2:46 PM | Permalink | Reply

        Re: John S. (#186),

        My understanding was that using (highly oversimplified) thermodynamics to try to disprove enhanced greenhouse was grounds for snippage on all threads. Calling Steve McIntyre.

      • DeWitt Payne
        Posted Sep 19, 2008 at 3:11 PM | Permalink | Reply

        Re: John S. (#186),
        Steve Mc., I’m finding the temptation to respond overwhelming.

        2. Power fluxes (watts/sq.m) translate into temperatures via the Stefan-Boltzman law. If by modeling fiat you impute non-existent “positive feedbacks” into the calculations, then you wind up with unrealistic power fluxes. Thus Houghton, based on Trenbeth and accepted by IPCC, shows a flux of 519W/sq.m in the atmosphere, which translates into a brightness temperature ~34C for a global annual average, even higher than that of the surface. Does anyone here believe that?

        Considering that incoming diffuse and direct solar radiation is included in the 519 W/m2 figure, yes, it’s quite easy to believe. Putting a small spot at 6,000 K in the field of view must increase the brightness temperature. What’s hard to believe is that apparently you didn’t consider this.

        • DeWitt Payne
          Posted Sep 19, 2008 at 6:38 PM | Permalink

          Re: DeWitt Payne (#189),

          Here’s a link to the pdf of Kiehl and Trenberth’s “Earth’s Annual Global Mean Energy Budget” to see where the numbers for the various energy fluxes came from and how they were measured (mostly) or estimated.

        • John S.
          Posted Sep 19, 2008 at 7:16 PM | Permalink

          Re: DeWitt Payne (#189), In your haste to get my heretical post #186 snipped, you mistakenly assumethat: a) I rely entirely on the crude, but effective, S-B approximation, and b) Houghton’s 519W/sq.m includes direct insolation. I don’t and it doesn’t. In fact, I rely on bolometric measurements and, to a lesser extent, on HARTCODE simulations. And I never argue with belief systems, only with purportedly scientific assertions.

        • DeWitt Payne
          Posted Sep 19, 2008 at 9:50 PM | Permalink

          Re: John S. (#195),

          Houghton’s 519W/sq.m includes direct insolation. I don’t and it doesn’t.

          Prove it. Provide a complete citation rather than just name dropping authors and techniques. Post links to relevant HARTCODE spectra with details of the calculation. The FAQ for IPCC AR4 WG1, which would seem to be definitive as far as what’s IPCC accepted, includes the cartoon from Kiehl and Trenberth cited above which shows that the surface absorbs globally on average 168 W/m2 from the sun and 324 W/m2 from the atmosphere. That’s 492 W/m2 total, not 519.

        • John S.
          Posted Sep 20, 2008 at 11:30 AM | Permalink

          Re: DeWitt Payne (#197), I’m not much of an internet surfer, and my clients do not permit me to reveal their data, so I’ll let Miskolczi’s summary of HARTCODE results (which you can find at a Hungarian site by Googling his name) speak for themselves. As for the Keil & Trenberth cartoon, reproduced on p. 58 of Houghton’s 1996 text, the sum of inputs into the atmosphere, net of albedo and the 168 W/m^2 of direct isnolation that you cite, is clearly 519. I’m surprised that you would resort to switching to the surface figure of 492. An doesn’t that discrepancy, which is a persistent feature of GCM results, bother you as an astute thermodynamicist?

          Your #193 post, which cites band-wing absorption of CO2 and calls GCM radiation transfer calculations “bullet-proof,” concerns itself with but a minor point in the full picture of system behavior that I was trying address. As you surmise correctly, the major uncertainty is in the moist adiabiatic lapse rate. Radiative balance results in hydrostatic imbalance, which drives convection in seeking to establish thermodynamic equilibrium via maximum entropy paths. The W/m^2 involved here dwarf any possible incremental GHG effects, and the total amounts closely balance the downward IR–an empirical result cited by Geiger’s classic text (Climate near the Ground) in the early pages.

        • DeWitt Payne
          Posted Sep 20, 2008 at 1:14 PM | Permalink

          Re: John S. (#202),Re: John S. (#202),

          So you’re saying that 519 W/m2 in is 67 absorbed from solar radiation plus 350 absorbed from the surface plus 24 sensible and 78 latent heat from the surface and that’s the number you plug into S-B to get a brightness temperature. Wrong. The brightness temperature depends on the direction and altitude of observation. From deep space looking only at thermal IR, the integrated flux density is 235 W/m2. But that number includes 40 W/m2 emitted directly from the surface, subtracting gives 195 W/m2 emitted by the atmosphere up. From the surface looking up, the integrated flux density is 324 W/m2. 324 plus 195 is, not surprisingly 519 and the energy in and out balances. Citing Miskolczi is grounds for putting you in my mental kill file. *plonk*

        • John S.
          Posted Sep 22, 2008 at 4:42 PM | Permalink

          Re: DeWitt Payne (#204),

          What I’m saying is that a blackbody hung in the atmosphere through which 519W/m^2 is steadily coursing would absorb all of it, not just what radiates to space. And you never answered my question about the discrepancy between that and the surface value of 492.

          When, at your behest in #197, I point to data that you don’t like, you put me on your kill list. Hmm, somehow I feel honored!

      • DeWitt Payne
        Posted Sep 19, 2008 at 6:28 PM | Permalink | Reply

        Re: John S. (#186),

        3. The commonly accepted range of figures ca. 3W/sq.m for the effect of doubling CO2 is merely a theoretical calculation based on capacity. The actual energy content of the additional CO2 would depend entirely upon presently unabsorbed energy in the 15-micron band. With that band nearly saturated even at 1930’s levels, there’s not much left to absorb. And as the very short time-constant of atmospheric temperature response to the diurnal cycle clearly shows, it’s not the atmosphere that provides the planetary temperature stability.

        The increase in absorption is primarily in the wings of the band, not the center. The amount of forcing also depends on the height and temperature of the tropopause. Given a known temperature and humidity profile, the radiative transfer calculations are bullet proof. One of the weaknesses of the GCM’s is whether they calculate these profiles correctly over time with increasing ghg’s. But that’s an entirely different argument.

      • Posted Sep 20, 2008 at 2:58 AM | Permalink | Reply

        Re: John S. (#186), my two cents as retired chemical engineer:

        point 3: as far as I know, the 3 W/m2 is based on measurements of absorption lines, be it in a laboratory, not on any theoretical guesses. Modtran gives a rough interpretation of the effect of CO2 and other greenhouse gases (water vapour) and clouds at different heights. See here.

        point 4: There is not the slightest reason why a moderate positive feedback (feedback factor smaller than 1) would lead to instability (a runaway reaction). I have worked with countless chemical reactions (polymerisation) of that type. Some of them were running away, but that was due to errors in composition and/or supply speed…
        The same for natural reactions: as long as the feedback factor is less than one, the overall effect will be an increase of the initial forcing, but no instability.

        For CO2, the influence of temperature on CO2 levels is about 8 ppmv/°C over long term in the past about one million years (based on ice core measurements). This includes long term changes in vegetation growth like moving tree lines, ice/tundra cover and deep ocean currents. For short time variations (1 month to years), the incluence is about 3 ppmv/°C, mainly caused by upper ocean absorption/desorption, superposed over the overall CO2 trend caused by human emissions.
        For extreme long time periods (millions of years) the position/subduction of continents and the weathering of mountains, plus the resulting wind/ocean current changes can shift the dynamic equilibrium in exchanges between the carbon reservoirs towards higher or lower levels for each of them, including the atmosphere.

        Without further feedbacks (positive or negative), the influence of CO2 on temperature is about 3 °C/280 ppmv, or near 1 °C/100 ppmv, which is the difference in CO2 level between an ice age and an interglacial. The real temperature difference was near 10 °C, thus CO2 was directly responsible for about 10% of the temperature increase/decrease of the transitions. This is hardly measureable, and is not detectable within the margins of error in ice core measurements for the last interglacial-glacial-interglacial transitions. Hansen (and all GCM’s) include (only) positive feedback factors and Hansen assumes that near 50% of the increase/decrease over the ice ages is from the influence of GHGs. This should be visible in any of the fine resolution ice cores, but it is not…

        • Pat Keating
          Posted Sep 21, 2008 at 6:25 PM | Permalink

          Re: Ferdinand Engelbeen (#201),

          No, that’s completely wrong. The line-by-line, no-feedback calculation yields about 1.2C for doubling CO2 from 300 to 600 ppmv, not the 3C you claim.

        • DeWitt Payne
          Posted Sep 21, 2008 at 8:18 PM | Permalink

          Re: Pat Keating (#207),

          I think he’s saying that the average temperature would be 3 C lower at 0 CO2 compared to 300 ppm. But that’s wrong too. A quick MODTRAN 3 calculation shows that 0 ppm CO2 (1976 atmosphere, constant water vapor pressure, 70km looking down requires a -7.1 C surface offset to balance the OLR to the level at 300 ppm CO2 (259.741 W/m2). Not to mention that a linear assumption of X C/100 ppm starting from zero is not a valid approximation. The idea that the fraction of greenhouse warming due to CO2 is constant as CO2 changes is one of those arguments that needs to be spiked.

  87. Larry Hulden
    Posted Sep 19, 2008 at 2:34 AM | Permalink | Reply

    When we go that far back in time as “snowball earth” (650-600 M.years ago, i didn’t check the exact figures) we are approaching other interesting issues. Before the cambrian explosion (nonterrestrian life) multicellular animal fossils are known only from Vendian which is after “snowball earth” times. So, what could be the reason for the multicellular animals appearing so late? Life is known at least from 3.4 billion years ago (Cyanophyta). Oxygen started to accumulate in the atmosphere about 1.8 billion years ago. Before that at least land life was impossible because of lack of ozon (UV would have killed life). There must have been some completely different environmental (?climatological) conditions during the time before snowball earth and after. Is it possible that oxygen reach high levels quite late, may be during snowball times?

  88. Chris D.
    Posted Sep 19, 2008 at 10:14 AM | Permalink | Reply

    The whole notion of “global dimming” is pretty interesting. Search Youtube for “global dimming”. It seems that some, including Hansen, believe that, were it not for all the aerosol junk that we put up into the atmosphere, we’d be experiencing an average of something on the order of 1.5 deg higher temps than we average now. Apparently, for the 3 days that the U.S. airspace was shut down, something noteworthy happened to the difference between max and min daily temps, as compared to normal. Seems like such a small sample. Has anyone independently looked at this?

  89. Chris D.
    Posted Sep 19, 2008 at 10:16 AM | Permalink | Reply

    Addendum: The 3 days post 9/11/01 terrorist attacks, that is.

  90. Sam Urbinto
    Posted Sep 19, 2008 at 11:03 AM | Permalink | Reply

    John S. a natural system with positive feedback?

    The answers depend a little on if this is limited to one type of application and what the definition of natural is. So I’ll just toss some stuff out.

    We could start with an ice-albedo positive feedback with some melting snow exposing dark ground that absorbs heat and makes more snow melt.

    Or then again, how about autocatalytic reactions like the binding of oxygen to hemoglobin or the degredation of aspirin into salicylic and acetic acids. Um, brain mirror neurons, coupled sugar molecules and proteins importing sugar into bacteria, nuclear reactions, plants, populations of prey and predators, adrenal glands, hurricanes, metabolic networks, phosphofructokinase in glycolysis, humidity as a function of altitude and temperature, contractions and oxytocin during childbirth, lactation during nursing, the clotting of blood, world population, population and agriculture, social networks, hyperinflation.

    • bender
      Posted Sep 19, 2008 at 11:21 AM | Permalink | Reply

      Re: Sam Urbinto (#180),
      The response will be “that’s not TRUE feedback, yadda yadda” …

    • John S.
      Posted Sep 19, 2008 at 1:46 PM | Permalink | Reply

      Re: Sam Urbinto (#180),
      The example of snow melting, exposing more ground, absorbing more heat is an example of a system component’s accellerating response to insolation, with no feedback (i.e. change in the power flux of the input) whatsover. Let’s not confuse cause and effect. You could expose all the ground you want, but, without insolation that would not “make” more snow melt. I’ll leave your other examples for your own contemplation.

  91. Sam Urbinto
    Posted Sep 19, 2008 at 1:44 PM | Permalink | Reply

    Ah, bender, yes, well I can only provide examples. :) But the definition of feedback is pretty clear….

    (Science: physiology) The return of some of the output of a system as input so as to exert some control in the process.

    Just to be fair to negative feedback, here’s one from biology.

    http://www.biology-online.org/4/1_physiological_homeostasis.htm

    And “Dr. Stein” says:

    Negative and positive feedback is a common mechanism in Endocrinology, to regulate the production (including synthesis and secretion) of such hormone(s). Since I am into that field, so what I explain is about hormone. I have no idea if there is another feedback things in other fields, but I think the principal is somewhat similar.

    In general this mechanism is used to maintain the constant level of hormone within our body, or homeostasis, to anticipate excessive or lack of hormone level, in which will lead to adverse effect(s) to target tissues.

    Here I give you an explanation using example, cos I think this will help you better rather than using a definition:

    Negative feedback:
    When the level of blood testosteron is increasing, this hormone will give a signal to hypothalamus and hypophyse to stop the production of GnRH and LH, respectively, to prevent the excessive level of hormone in blood. In contrast, when the level of blood testosteron is decreasing, this hormone will give a signal to hypothalamus and hypophyse to stimulate the production of GnRH and LH, respectively, so the hormone level will increasing to the normal level, then it will be maintain in that level.

    Positive feedback:
    ~ Before ovulation, ovarium secretes estrogen to stimulate the maturation of the ovum. The current level of estrogen will give a signal to hypothalamus and hypophyse to stimulate the production of GnRH and FSH, respectively, so the estrogen level will be increasing til reaches the peak. This is when ovulation occurs.

    ~ After ovulation, ovarium secretes progesteron to stimulate the growth of endometrium. The current level of progesteron will give a signal to hypothalamus and hypophyse to stimulate the production of GnRH and LH, respectively, so the progesteron level will be increasing til reaches the peak.

    When progesteron reached the peak, it will give a negative feedback to the production of FSH, so that the production of estrogen. This estrogen will stimulate the contraction of uterine muscles, so this is when the menstrual cycle begins.

    I hope I am not confusing you. Please draw your conclusion to define the negative and positive feedback, so I know you got my point. Thank you and good luck with your study

  92. bender
    Posted Sep 19, 2008 at 1:55 PM | Permalink | Reply

    #183 Not at all, Sam. Told ya: #184.

  93. bender
    Posted Sep 19, 2008 at 3:06 PM | Permalink | Reply

    Sounds like he’s saying that from a macroscopic planetary perspective no feedbacks are possible. Which is true, but irrelevant for someone interested in examining meso-scale thermodynamic cause-and-effect, where the sorts of feedbacks that Sam tried to analogize are valid. Dismissing Hansen’s testimony because it uses language that doesn’t translate well at the planetary thermodynamic scale is a red herring.

    I do apologize if there’s something brilliant in John S’s argument that I’m not understanding. I guess I’m not smart enough to see it.

    • DeWitt Payne
      Posted Sep 19, 2008 at 3:13 PM | Permalink | Reply

      Re: bender (#188),

      If this doesn’t get the snippage started, nothing will.

      I do apologize if there’s something brilliant in John S’s argument that I’m not understanding. I guess I’m not smart enough to see it.

      Who are you and what did you do to the real bender?

  94. bender
    Posted Sep 19, 2008 at 3:22 PM | Permalink | Reply

    If you are only interested in the long-term equilibrium behavior of a system it is understandable that you would think that fast and slow feedback processess could be dismissed as meaningless and superfluous. However we are interested in the system’s behavior at all time scales, from daily weather to the whole history of earth paleoclimate. I think Hansesn has excellent command of the concepts in his testimony.

    [DWP, I scale my behavior to try to match that of my opponent.]

  95. anna v
    Posted Sep 20, 2008 at 2:31 AM | Permalink | Reply

    bender:
    September 19th, 2008 at 11:34 am 182

    Re: anna v (#164),

    ” I find it very hard to think of a mechanis by which heat can be transferred to lower levels and under the ice if it does not affect the level studied. Conduction, convection, are the only ways I can think of. To heat the water, the metal kettle gets hot and transfers the heat to the water. I cannot see a way to keep the metal cooling and get heat to the water.”

    Time delays in, say, the THC. The surface waters were warm. That warmth has since been subducted to the depths, out of the region where probes are currently located. A time delay is a reasonable proposition given what we know about the ocean’s time constant for deep mixing.

    And why would time delays not pass through the levels studied? Subduction? Is it magic? would it not heat first the level studied? Time delay would appear as such time delay in that level.

    But I am speculating. The point is that there is a shared burden of proof on those who want to conclude that the oceans are cooling to consider the whole ocean. That the surface temperatures are cooling now does not mean the depths are not warming.

    I think there is a logical falacy in your last statement, except if you mean volcanism. I would accept “have been warmed previously” but not concurrently warming. And as I said this warming should appear on the record of the level studied anyway.

    • bender
      Posted Feb 25, 2009 at 7:13 AM | Permalink | Reply

      Re: anna v (#200),

      I think there is a logical falacy in your last statement

      Nope. If there is, then point to it. [Oh, but there is a spelling error in your last statement.]

  96. John S.
    Posted Sep 20, 2008 at 11:31 AM | Permalink | Reply

    I’ll reply to other posts when I have more time, but not today.

  97. Peter Lloyd
    Posted Sep 21, 2008 at 11:31 AM | Permalink | Reply

    Orbital conditions now are, indeed, conducive (albeit weakly6) to initiation
    of ice sheet growth in the Northern Hemisphere

    If he is talking about glaciers and polar ice caps, not sea ice, which can grow any time under appropriate short-term conditions, then not for over 400,000 years have orbital conditions been LESS conducive to ice sheet growth.

    We are heading for a somewhat rare interglacial – the fourth (the warmest) in the four-strong group that cycles every 415,000 yrs. approx. The nadir of the last ice age occurred at an orbital eccentricity of 0.045, the lowest (i.e., warmest) for 400,000 yrs; since when we have been warming as eccentricity decreases to the current 0.016, on its way to the next peak interglacial which will accompany an eccentricity of well under 0.01, possibly down to 0.005 – a virtually circular orbit and, again, the least eccentric for 400,000 years. This will occur in 25,000 years’ time and will be a real sizzler (excuse technical jargon) for 10,000 years on each side of minimum mean orbit radius. Even if we manage to suck out all the CO2 out of the atmosphere by then. (For what that would cost, I’ld rather have very efficient air conditioning supplied by lots of nuclear/deep geothermal energy, but that’s just my strange attitude).

    Those 20,000 years at very low eccentricity will encompass just about a whole precession cycle, so both poles will get a serious blast of solar.

    There is no chance that serious glaciation/ice cap formation can happen under those conditions. That is unlikely to begin until another 25,000 years after peak interglacial, when the climate will be returning to much the same as now, except on the way down in temperature to the next ice age. Now, that’s when the real problems will occur! That’s when the alarmists will say “There, we told you – Hansen was right all along!” They’ll probably build a statue to him. In ice.

    Seriously, I take on board Steve’s comments on Hansen’s achievements, but if he’s so good and been working so long in the climate business, is he not be aware of the above? And, being aware, how can he make the above statement on such a critical occasion?

    Actually, I guess I know the answer. And it’s sad.

    By the way, none of the above is fancy theory. Standard, well-established orbital mechanics plus a little high-school physics. References as follows:-

    Berger & Loutre, Quaternary Science Review, vol.10, 297-317, 1991
    Berger & Loutre, Science, vol.297, Aug.2002
    Milankovitch, Canon of Insolation and the Ice Age problem, 1941(Engl.1969)

    • bender
      Posted Sep 21, 2008 at 1:29 PM | Permalink | Reply

      Re: Peter Lloyd (#205),

      is he not be aware of the above? And, being aware, how can he make the above statement on such a critical occasion?

      Did you try asking the high priests of the consensus at RC? It’s always fun to learn what doesn’t pass through their filter.

      • Peter Lloyd
        Posted Sep 22, 2008 at 7:42 AM | Permalink | Reply

        Re: bender (#206),

        Bender-

        I sat through enough air raids nearly seventy years ago, and survived without having my head blown off – whether anything was left in it is another argument. It would be plain stupid to volunteer to repeat the experience.

  98. Posted Sep 22, 2008 at 10:12 AM | Permalink | Reply

    I found Hansen’s paper much better than expected, given his record of outlandish claims. However, I still have some major issues with it:

    1) The idea of a CO2 driven climate for the past 65 my and the weak Milankovitch forcing plus strong CO2/albedo feedbacks as the explanation for the glacial cycles is portrayed by Hansen as firmly established science. My understanding is that it is much less solid than that. Svalgaard’s opinion on the solidness of the Milankovitch thesis and the rest of Hansen’s argument would be helpful, if he’s around.

    2) Hansen’s following claims are hardly supported by evidence: “ice sheets are disintegrating in both hemispheres” and “current events occurring on the ice sheets and in the oceans bordering the ice sheets, provide strong evidence that continued global warming is likely to initiate substantial ice sheet response”. SH ice sheets, and particularly the Antarctic one, as a whole, are pretty stable, if not increasing. Temperatures in Antarctica are not increasing and the SH sea ice area shows a statistically significant positive trend during the satellite period. There is much speculation about the West Antarctic ice sheet, as he admits himself, but his statements are incorrect, according to the best available data. I think that here, and further down, in his 5th section, he shows some disconnect with reality and gets a bit carried away by the desire to view his long-held alarmist theory supported by evidence.

    Also his idea that all we need to avert a new ice age is “a single CFC factory” is totally new to me. How well established is that?

    3) I fail to understand how the rather well-documented abrupt end of the last glacial cycle fits in his orbital/CO2/albedo theory. If anyone can explain how a glacial cycle can suddenly come to an end through a slow GHG/albedo feedback/forcing, I’d greatly appreciate it.

    • Stan Palmer
      Posted Sep 22, 2008 at 11:49 AM | Permalink | Reply

      Re: Mikel Mariñelarena (#210),

      3) I fail to understand how the rather well-documented abrupt end of the last glacial cycle fits in his orbital/CO2/albedo theory. If anyone can explain how a glacial cycle can suddenly come to an end through a slow GHG/albedo feedback/forcing, I’d greatly appreciate it.

      This is characteristic of positive feedback. It is used commonly in electronic circuits to produce a fast output from a slowly changing signal. The Schmitt Trigger is a frequently used example of this.

      • Stan Palmer
        Posted Sep 22, 2008 at 12:21 PM | Permalink | Reply

        Re: Stan Palmer (#212),

        Of course, this does create the question of how the positive feedback is inhibited to create stable output states or in Hansen’s case stable climates between transitions. The Shcmitt trigger exhibits a common solution in electronic circuits for this. So the question is not what can cause a rapid transition. The arm-waving that one hears about positive feedbacks from albedo effects could do this.The real question is how this feedback is inhibited to produce the stable climate periods.

        Tipping points are easy to create. Stability between tipping points is much more difficult and will require much deeper analysis than the current arm-waving.

        • bender
          Posted Sep 22, 2008 at 12:40 PM | Permalink

          Re: Stan Palmer (#213),

          The real question is how this feedback is inhibited to produce the stable climate periods.

          What “stable” climate periods would these be?

        • Stan Palmer
          Posted Sep 22, 2008 at 12:44 PM | Permalink

          Re: bender (#214),

          The stable climate periods that are indicated on the Mann Hockey stick. These are the important periods that that analysis discovered.

        • bender
          Posted Sep 22, 2008 at 12:52 PM | Permalink

          Re: Stan Palmer (#215),
          Hmm, I wasn’t prepared for that sort of reply. Never mind …

      • Posted Sep 23, 2008 at 10:06 AM | Permalink | Reply

        Re: Stan Palmer (#212),

        Thank you, Stan. That makes sense, in theory. Hansen himself speaks of the possibility of tipping points causing non-linear effects in the climate system.
        However, that brings us back to square one, I think.

        In such a CO2-dependant climate, human emissions of GHGs should have already caused a much bigger warming. And they haven’t, as Lindzen keeps pointing out. Much though I’ve tried to have this discrepancy between theory and observations clarified to me by some AGW-proponent, I’ve only received more warm-waiving and a total lack of quantitative analyses.

  99. Sam Urbinto
    Posted Sep 22, 2008 at 11:12 AM | Permalink | Reply

    184 John S.:

    Without insolation? Sorry, I’m on the real Earth.

    It should go without saying I’m not claiming the sun’s output is being fed back into its input.

    How about a pot of with a lid versus one without? In that case, as long as I know what the heat source is putting out, I’m really not concerned with it in any single given circumstance.

    Again:

    The return of some of the output of a system as input so as to exert some control in the process.

    Define the system. Does any of the output influence that specific system as an input? Then you can call it feedback. Negative brings it towards equilibrium. Positive moves it away. Nothing much more to contemplate.

    • John S.
      Posted Sep 22, 2008 at 4:44 PM | Permalink | Reply

      Re: Sam Urbinto (#211),

      There’s an important distinction being missed, which I’ll explain when I find time tomorrow.

    • John S.
      Posted Sep 23, 2008 at 3:33 PM | Permalink | Reply

      Re: Sam Urbinto (#211),
      Feedback in system science has a very specific literal meaning: the real-time return of the output signal (with or without some intervening filtering or gain-setting in the loop) for algebraic summation with the input signal. It is not just anything that affects the output signal power or instantaneous magnitude, as many in “climate science” have come to believe.

      The definition you quoted is oriented toward control systems. They have output-sensors which activate external power sources to alter the input in order for the output to conform to a desired result. While biological systems, which may have positive feedback between various subsystems (with on/off switches to bound the response), are often control systems, energy-conserving natural systems don’t operate that way.

      Ludicrous as it may sound to you, a rigorous system model of the effect upon surface temperatures from albedo changes due to snow/ice ablation will not have any feedback loop whatsoever back to the fundamental input of insolation. (There are other inputs, of course, but they all draw their power from insolation). And that is as it should be, because the insolation signal remains unaffected. What does change is the system characteristic, which determines the instantaneous response to the input. (One would expect to see a huge accelleration in that nonlinear characteristic around zero C.) Such a system is properly called time-varying. Modeling it becomes much more complicated, but miscasting it as a feedback system would yield grossly misleading results.

      Hope this clarifies what I’ve been saying all along.

  100. bender
    Posted Sep 22, 2008 at 1:01 PM | Permalink | Reply

    Looking into deep time, long past the 1000 years of MBH work, the Hansen testimony illustrates an ocean temperature recon in Fig 1 that looks anything but stable. Now let’s talk about stabilizing negative feedbacks.

  101. John S.
    Posted Sep 22, 2008 at 4:26 PM | Permalink | Reply

    Ferdindand (re: #202),

    Experience is invaluable in understanding reality and dispelling academic conceits. Your comments thus are welcome.

    Knowing nothing about the manufacture of polymers, I’m hard-pressed to identify the feedback loop in that process. To me it’s a “black box” whose input is the chemical energy of the raw materials and whose output is that of the finished polymer, perhaps augmented by reaction. Surely, that output is not being fed back into the input. In speaking of positive feedback, are you referring to the chemical reaction itself or to a control system for regulating the injection of catalyst and/or raw materials, or both? Please enlighten me by specifying the feedback loop and all power sources, or by particularizing the general input-output transfer function

    H(s) = G(s)/[1-kL(s)G(s)]

    of the system, where G is the (one-sided) Laplace transform of the open-loop power flux, L is that of the feedback loop, and k is a regulating feedback gain constant. Is stability in your system attained by k<1, or by the overall system gain (the normalized integral of absolute values of H(s) on the imaginary axis) satisfying that condition?

    Generally, system stability is ascertained not by any simple gain criterion, but by satisfying those of Routh-Hurwitz or Nyquist for linear systems and Lyapunov or Popov for nonlinear ones. The fundamental BIBO stability principle requires that all bounded inputs produce a bounded output. If any bounded input whatsoever can produce an unbounded output, the system is unstable. Energy-conserving systems are invariably unstable under positive feedback. Dissipative systems need not be. Even negative-feedback systems can be unstable. Losses to entropy often make theoretically energy-conserving systems behave dissipatively in the real world. Non-nuclear natural systems can only recirculate input power internally, without multiplying it globally, and are never positive-feedback systems. Man-made systems (including ill-posed computer models) with positive feedback rely on various external devices to maintain bounded output. System stability is by no means a simple matter.

    Regarding doubled CO2, I’m aware that the increase in IR power absorption (which I quoted from imperfect memory) was determined by careful laboratory experiments. But in vitro values become, in effect, theoretical calculations when they’re applied by GCMs to model vastly greater columns of atmosphere, where cloud droplets and ice crystals, various aerosols and particulates–not to mention highly variable water vapor–appear in situ. By analogy, one can accurately determine how much more water a greatly increased dam-height can hold. But that doesn’t mean that runoff from the rainfall basin will ever produce that amount.

    I agree with you that CO2 accounts for only ~10% of the atmosphere’s capacity to absorb and re-radiate IR. Water vapor accounts for ~8 times as much, on a global average. Empirical attempts to determine the in situ “sensitivity” of atmospheric temperatures to changes in CO2 from ice-core reconstructions thus run into the obvious problem of separating the effects of these two factors. Modern bolometric measurements show variations up to 40W/m^2 at some sites due to changes in humidity alone. Without adequate knowledge of the latter factor, the results of such attempts rest on highly precarious grounds. Simply dividing the total rise in temperature by that of CO2 during a glacial half-cycle gives us nothing of thermodynamic significance. At finer, quasi-millenial intervals, the regressional correlation between changes in these two variables is pitifully low (R^2<0.2) and the “sensitivity” correspondingly falls to <1C/30ppmv. This is purely a statistical relationship, however, not to be confused with a system response characteristic.

    A less obvious–and insurmountable–problem shows up in the celebrated Vostok data: the temperature signal leads that of CO2 by many centuries. This tell us that CO2 cannot be the principal factor in climate change. Embarassed proponents of the AGW thesis are now surpassing the post hoc, ergo propter hoc fallacy by proferring its absurd inverse: before it, therefore because of it. Such “reasoning” ignores the irreversibilty of the arrow of time, which is the underpinning principle of thermodynamics. No physical system can operate on future forcings or change the past. The fanciful notion of “heat in the pipeline”–it takes centuries for deep-ocean temperatures to adjust–may salvage the AGW thesis amongst die-hard, soft-science adherents. Those who don’t ignore basic principles (and understand that heat has no momentum, nor can flow from a colder source to warm the surface), recognize that it’s a laughable attempt to invest CO2 with divine powers of anticipation.

    While various conjectures run rampant in all quarters, very little is known on a rigorous scientific basis about the factors that actually drive persistent global climate change. If you have any well-developed ideas, I’d be happy to discuss them, as time permits.

    • team bender
      Posted Sep 22, 2008 at 4:39 PM | Permalink | Reply

      Re: John S. (#218),

      A less obvious–and insurmountable–problem shows up in the celebrated Vostok data: the temperature signal leads that of CO2 by many centuries.

      Not only is it obvious, it’s been discussed to death.

      Re: Steve McIntyre (#19):

      Please move on from Co2 lead-lag discussions, which I’m weary of.

  102. John S.
    Posted Sep 22, 2008 at 4:28 PM | Permalink | Reply

    Pardon the italicization mess-up.

  103. Steve McIntyre
    Posted Sep 22, 2008 at 4:51 PM | Permalink | Reply

    Once again, please take these sort of discussions to the Bulletin Board if you are arguing personal theories about what is and isn’t possible. I can’t take the time to intervene in these discussions and they tend to give a very bad impression to outside readers, to say the least.

    • John S.
      Posted Sep 23, 2008 at 3:42 PM | Permalink | Reply

      Re: Steve McIntyre (#223),

      Steve,

      In his testimony, Hansen talks system science talk, but fails to walk its demanding walk. Discussion of this disconnect seems very much on-topic.

      System analysis rests on rigorous mathematical foundations presented by Norbert Wiener in his seminal book The Fourier Integral and Certain of Its Applications (1933) and expanded upon in Cybernetics (1948). (Because of the color of its covers and its mathematical demands, the former tract was called the “yellow peril” by students of the post-war generation.) Properly applied in many fields of science, the analytical techniques have a spotless track-record of performance, as the mountainous literature attests. Misapplied, they lead to conceptual confusion and unreliable results presented under the color of authority.

      By patently ignoring the fundamental requirement for realizable (i.e., causal) systems and imputing non-existent feedbacks, Hansen & Co. often posit unsupported explanations of the climate system that are little more than climatespeak. System realizability is quite intimately connected to the principle of irreversibility in thermodynamics. I hope you don’t consider my (#218) statement that “no physical system can operate on future forcings or change the past” to be a “personal theory.” That would be flattering me beyond all reason.

      • Mark T
        Posted Sep 23, 2008 at 10:36 PM | Permalink | Reply

        Re: John S. (#231),

        “no physical system can operate on future forcings or change the past” to be a “personal theory.” That would be flatering me beyond all reason.

        Hehe, wouldn’t you love to be credited with the principle of causality, eh John S.? :)

        I actually argued with a guy regarding this once. He was a philosophy major entranced by Hume’s works. I suppose folks like that come from the “what causes the causes” viewpoint.

        Mark

        • John S.
          Posted Sep 25, 2008 at 2:20 PM | Permalink

          Re: Mark T (#235),

          Mark,

          Such “originality” would make quite an item in anyone’s CV!

          On a more serious note, GCMs have a long history of chronic problems in keeping their outputs bounded when run on climatic time-scales. While some of the problems are traceable to numerical instabilities in iterative Navier-Stokes solutions on a coarse global grid, these affect merely the transport of heat. The fig leaf of chaos cannot hide the ubiquitous discontinuities of model temperatures at the surface-atmosphere interface or global accumulations of energy (positive Lyapunov exponents) under steady-state inputs and invariant response characteristics. These persistent problems arise from the systematic imbalance of power fluxes attributed to moist convection/precipitation and to downward IR. (Assumptions of fixed relative humidity are egregiously unrealistic.) In other words, the models are not cohesive energy-conserving systems. All sorts of ad hoc procedures are used to rein in outputs, but the problem has not been solved at its root.

          While I’m attuned to the skeptical rationalist thread that runs from Kant to Popper, the empirical/pragmatic views of John S. Mill and Charles S. Peirce to problems of scientific inference cannot be ignored in bona fide climatology. Alas, with boundless fanciful attributions to AGW, what we are witnessing is a philosophy which stems from roots of shamanism.

          Just as the S/N ratio of the discussion finally rises well above unity (thanks to your and some of Sam Urbinto’s contributions), I’m regrettably forced to abandon it in order to prepare for a project overseas.

  104. Posted Sep 22, 2008 at 4:56 PM | Permalink | Reply

    Bender,
    Pielke has been clear on that: the OHC is the only effective metric to measure global warming (or cooling).
    In the CO2 depending climate hypothesis there is no way for extra heat to escape away from the climate system.
    Every extra Joule must be accumulating in the atmosphere or the ocean. Since what matters down on the Earth is the ocean, let’s deal with that.
    Josh Willis explanation that extra warming was going down in the deep ocean is unsupportable because sea level data are essentialy coherent with ARGO ocean temperature: no temperature increase for ARGO (that is the most extensive way we are measuring ocean temperature), no sea level increase.
    Natural variability in air temperature (the lack of significant warming in the last decade) can be regarded as noise in the monotonic increase due to GHGs, but a one year total (ocean) heat content change can’t.

    In a subordinate hypothesis that heat is flowing in the deep ocean, that is a very different case than heat in the pipeline, because heat down there is not available in the next future.
    To this regard, the way heat can flow down is through the turbulent friction between different layers of water mixed by tides, eventualy enhanced near the continental platforms. Scientists don’t agree, however, on the magnitude of this phenomenon.

    If the extra GHG forcing is not accumulating in the climate system, as it seems, then the system behavior is different form what are postulating Hansen and the like and negative feedbacks are prevailing (or a negative forcing of some sort is acting).

    • bender
      Posted Sep 22, 2008 at 5:04 PM | Permalink | Reply

      Re: Paolo M. (#224),
      I have taken to The Blackboard. Steve M does not like theorizing here.

      • DeWitt Payne
        Posted Sep 22, 2008 at 9:05 PM | Permalink | Reply

        Re: bender (#225),

        I have taken to The Blackboard.

        Good luck with that. I’ve tried and it’s hopeless, as you can see above.

  105. Posted Sep 23, 2008 at 11:14 AM | Permalink | Reply

    Bender,

    “Steve M does not like theorizing here”

    And who is theorizing here?

    Roger Pielke?

    Almost all I wrote is firmly based on peer reviewed science, as everyone who reads Pielke’s weblog knows, and is right on the topic of this thread (I think).

    You can start from here.

    Now I will have a look at The Blackbord…

  106. Sam Urbinto
    Posted Sep 23, 2008 at 11:31 AM | Permalink | Reply

    John S: A pot of water with a lid and without under the same circumstances is not about the constant heat source. The lid provides more feedback to the water than the heated higher humidity air does when there is no lid, which would be different if a cold dry air was blowing over the top of the pan. :)

    I just think you’re being a little pedantic about how you’re defining feedback. Think time/area scales, and subsystems; micro vs macro. Gawd, this reminds me of the LTE discussions on the bulletin board….

    But as to your “in vitro values…become theoretical calculations…vastly greater columns of atmosphere, where cloud droplets and ice crystals, various aerosols and particulates–not to mention highly variable water vapor–appear in situ.” and “This is purely a statistical relationship, however, not to be confused with a system response characteristic. ” and “very little is known on a rigorous scientific basis about the factors that actually drive persistent global climate change.”

    I agree.

    These and many other matters can and have been discussed over at the BB in depth.

    http://www.climateaudit.org/phpBB3/

    • John S.
      Posted Sep 23, 2008 at 3:58 PM | Permalink | Reply

      Re: Sam Urbinto (#229),

      Sam,

      Sorry for missing your latest before I posted. I, too, despise pedantry. But I also hate analytic confusion getting in the way of progress in science–or understanding between gentlemen.

      Gotta attend to other matters! I won’t be on this thread for a while.

  107. bender
    Posted Sep 23, 2008 at 4:42 PM | Permalink | Reply

    John S is invoking a very narrow lexicon. His disagreement with Hansen is purely semantic. It makes no sense to parse endlessly the feedback definition when there are substantive issues of greater concern.

  108. Mark T
    Posted Sep 23, 2008 at 10:33 PM | Permalink | Reply

    I disagree, bender. The terminology is not only used incorrectly, it is also applied incorrectly (based on what I have read). Many in the climate sciences fail to grasp what is really happening in feedback systems. John V’s nonsensical “analyses” on the topic are not completely atypical of the types of confusions I’ve witnessed in this realm. If you get the meaning of feedback (and what it can do) incorrect, you are also likely to be applying it incorrectly, or failing to understand what you are actually analyzing. Sometimes semantics are important, and when untrained programmers implement complex systems based on feedback witout understanding the basis behind the semantics, results will always be suspect.

    Mark

  109. conard
    Posted Sep 24, 2008 at 2:53 AM | Permalink | Reply

    MarkT

    I saw the opportunity to make a bad Hume related pun and it turned into three comments:

    1. Public Utility vandals increase Public Utility. (kim– a little help?)

    2. Popper salvaged the scientific method from Hume’s attacks on induction but agreed that the problem of causation did not have a positive solution, what caused the cause is not really on the table. I have not kept up with literature– perhaps a lurking Bayesian Philosopher or Statistician could provide homework to bring us up to speed on the development of p(h/e|c).

    3. Skimming Hansen’s testimony and considering the outcome it is hard to believe that Hansen’s methods and tools are objective and independent of personal views– I am sure that early in his career this was not the case. By all appearances, in the latter years of his career, the authority of his science rest on a social foundation rather than an objective one. Kuhn had much to say on this. Feyerabend even more. Popper would, I assume, be appalled at the notion of a consensus confirming anything. Brining us back to my #1– How then to calculate the probability of a high value for the public utility of public utility vandalism?

  110. Sam Urbinto
    Posted Sep 25, 2008 at 3:58 PM | Permalink | Reply

    Like my issues with refering to the global mean temperature anomaly as temperature or a rise in that trend as warming, there are certain ways to put certain things. I say that calling a trend rise (especially of the land/sea anomaly) “warming” rises far above the common use of feedback as we might understand it (or analogize it). I don’t disagree how things are phrased can possibly make a difference. I don’t agree this is one of them.

    To explain that some of the longwave infrared radiation leaving the ground being returned, or water vapor equalizing lower tropospheric temperatures at spot A or spot B as “feedback” is a different thing.

    But like with LTE, the scope of the issue being understood is the main thing; what are the spatial and temporal characteristics, the conditions we are operating under. Including the unspoken assumptions and such.

    I am not of the opinion that using the word “feedback” to describe some output of a system influencing the system to keep it at some type of equilibrium or moving it away from such is confusing or sneaky.

    The real question is; if SE almost always passes, and SEM almost always fails, does it matter which you use? :D

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