GRL Study: Dramatic climate change is unpredictable

Update: PDF of this paper is available, see link below

This is a schematic picture of the climate represented by the red ball. The climate can be located in two different states, the two valleys on each side of a hill. In the first scenario the climate is like a seesaw. If the outside influences increase or, for example, increased CO2 makes the weight heavier on the other side, the seesaw will tip forcing the climate over into the other state. The climate change would be predictable. In the second scenario, the hill is fixed and a series of small chaotic kicks from wind and weather could cause it to roll over into the other state. This climate change is unpredictable. Mathematically speaking, the first scenario is a "bifurcation" and the second scenario "noise-induced transition". Credit:Peter Ditlevsen, PhD. Dr. Scient. Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen

The fear that global temperature can change very quickly and cause dramatic climate changes that may have a disastrous impact on many countries and populations is great around the world. But what causes climate change and is it possible to predict future climate change? New research from the Niels Bohr Institute at the University of Copenhagen shows that it may be due to an accumulation of different chaotic influences and as a result would be difficult to predict. The results have just been published in Geophysical Research Letters.

For millions of years the Earth’s climate has alternated between about 100,000 years of ice age and approximately 10-15,000 years of a warm climate like we have today. The climate change is controlled by the Earth’s orbit in space, that is to say the Earth’s tilt and distance from the sun. But there are also other climatic shifts in the Earth’s history and what caused those?

Dramatic climate change of the past

By analysing the ice cores that are drilled through the more than three kilometer thick ice sheet in Greenland, scientists can obtain information about the temperature and climate going back around 140,000 years.

The most pronounced climate shifts besides the end of the ice age is a series of climate changes during the ice age where the temperature suddenly rose 10-15 degrees in less than 10 years. The climate change lasted perhaps 1000 years, then – bang – the temperature fell drastically and the climate changed again. This happened several times during the ice age and these climate shifts are called the Dansgaard-Oeschger events after the researchers who discovered and described them. Such a sudden, dramatic shift in climate from one state to another is called a tipping point. However, the cause of the rapid climate change is not known and researchers have been unable to reproduce them in modern climate models.

The climate in the balance

“We have made a theoretical modelling of two different scenarios that might trigger climate change. We wanted to investigate if it could be determined whether there was an external factor which caused the climate change or whether the shift was due to an accumulation of small, chaotic fluctuations”, explains Peter Ditlevsen, a climate researcher at the Niels Bohr Institute.

He explains that in one scenario the climate is like a seesaw that has tipped to one side. If sufficient weight is placed on the other side the seesaw will tip – the climate will change from one state to another. This could be, for example, an increase in the atmospheric content of CO2 triggering a shift in the climate.

In the second scenario the climate is like a ball in a trench, which represents one climate state. The ball will be continuously pushed by chaos-dynamical fluctuations such as storms, heat waves, heavy rainfall and the melting of ice sheets, which affect ocean currents and so on. The turmoil in the climate system may finally push the ball over into the other trench, which represents a different climate state.

Peter Ditlevsen’s research shows that you can actually distinguish between the two scenarios and it was the chaos-dynamical fluctuations that were the triggering cause of the dramatic climate changes during the ice age. This means that they are very difficult to predict.

Warm future climate

But what about today – what can happen to the climate of the future? “Today we have a different situation than during the ice age. The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago, when the climate was very warm and alligators lived in England. So we have already started tilting the seesaw and at the same time the ball is perhaps getting kicked more and could jump over into the other trench. This could mean that the climate might not just slowly gets warmer over the next 1000 years, but that major climate changes theoretically could happen within a few decades”, estimates Peter Ditlevsen, but stresses that his research only deals with investigating the climate of the past and not predictions of the future climate.

###

Contact:

Peter Ditlevsen, climate researcher, PhD. Dr. Scient., Associate professor, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, +45 3532-0603, +45 2875-0603, pditlev@gfy.ku.dk

Link to article in Geophysical Research Letters: http://www.agu.org/journals/gl/papersinpress.shtml#id2010GL044486

Update: PDF of full paper now available here

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64 thoughts on “GRL Study: Dramatic climate change is unpredictable

  1. some chaos stuff that is not so chaotic
    from walterdnes over at solarcycle24.com
    Here’s another idea. It’s so glaringly obvious that I wish I had made the connection. But connecting apparently unconnected stuff is the sign of true genius. A post by gus in the “Katla Watch” thread… http://solarcycle24com.proboards.com/ind….1322&post=54230

    I’ve read that it is thought to be the natural decay of radioactive elements inside the Earth that keeps the planet hot enough for volcanic action. http://www.tulane.edu/~sanelson/eens211/earths_interior.htm

    Here is new proof that increased solar activity slows the decay rate and that the decay rate is higher with a quiet sun like at the current solar minimum.

    http://www.sciencedaily.com/releases/2010/08/100825093253.htm

    The increased decay rate due to the current solar minimum should result in more heat created inside the Earth that could result in higher volcanic action and so increased risk for Katla to go BOOM!!!

  2. here’s what I read:

    theoretical
    modelling
    might
    if
    if
    could
    may
    could
    theoretically
    could

    sounds pretty solid to me.

  3. “The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago,”

    Right, and we had CO2 much higher than now during three periods on the last 200 years. So, this argument is bogus. Discounting and ignoring virtually all direct chemical Co2 bottle data is just too pat a way to create a false conclusion. It begs credibility to assume ice core indirect data to be more accurate than direct chemical bottle data. Making such sweeping unsupportable statements, the authors could be accused of simply flowing a political agenda/party line.

    “So we have already started tilting the seesaw . . .”

    As there is no evidence that CO2 has a great influence, more likely small or none, on the climate, they really need to stop with the extended imaginings and be more realistic/conservative in their musings. Here, Elvis has surely left the building. They are marching towards fear-mongering.

    (Peter Ditlevsen) “stresses that his research only deals with investigating the climate of the past and not predictions of the future climate”

    After making these alarming predictions and pointing at CO2 as a possibly facilitator of tipping (in my opinion a very weak idea), he then waffles and retreats, having done the damage. The predictions should never have been made, if they required a disclaimer, particularly as it feeds the alarmist agenda – unless that was the goal, of course.

  4. Sorry–I don’t believe the climate acts like a trenched seesaw harboring a ball that moves from one side to the other. I believe the climate acts more like a single ball-harboring trench, and forcing the ball to one side of the trench or the other forces it above the minimal state, after which it returns to that minimal state after the force is removed.

  5. I suspect that what I get out the article will be different than what a warmer will decipher.

    I expect CAGW proponents will focus on the possibility of a quick warming cycle caused by CO2.

    I get that:
    “a result would be difficult to predict” “due to an accumulation of different chaotic influences ” – in other words, models are sophisticated enough for the science.

    That the CO2 is only an example of a quick cycle, while admitting that life did just fine in the former warm periods.

    That the bulk of earth’s past has been ice ages.

    And Dr. Ditlevesen states that his work is of past cycles, not future predictions

  6. Would climate change be “dramatic” if it was predictable ? And don’t “unpredictable” and “chaotic” go hand in hand ?

    Maybe they are discovering what we already know.

    It seems reasonable that if earth’s orbit suddenly changes or some asteroid or comet crashes into the earth; that “dramatic” climate changes might occur. It also seems reasonable that events like that might tend to be unpredictable.

    But other than that I don’t see how one could plan for some future unpredictable possibly dramatic event; the climatic result of which we cannot at this time forsee.

  7. I’m going to regret asking this , but how does onr drtermine the makeup of the atmosphere from fifteen million years ago ? Accurately , that is .

  8. Correction:

    I get that:
    “a result would be difficult to predict” “due to an accumulation of different chaotic influences ” – in other words, models are NOT sophisticated enough for the science.

  9. “”” New research from the Niels Bohr Institute at the University of Copenhagen “””

    What new research ? Computer modelling is not research. Computer simulation can be valuable; once the science behind the model is validated by observations. I do computer simulations all day long; but they are based on the mathematics of geometrical optics and physics that has been validated for over 300 years or more. The simulations are done to complete a design based on well understood science; and not to discover any “new” unknown science.

  10. wayne says:
    August 30, 2010 at 9:14 am
    How do the day dreams of climatologists get published so easily?

    Peer review. In the mutual addoration society, they enable each others dreaming.
    We don’t want their feeling hurt.

  11. P Walker says:
    August 30, 2010 at 9:10 am

    I’m going to regret asking this , but how does onr drtermine the makeup of the atmosphere from fifteen million years ago ? Accurately , that is .

    You need three ingredients: ice cores, guesswork, and arrogance.

  12. Regarding the “10-15,000 years of a warm climate like we have today” , where are we in this time period today ?

  13. Anymore, whenever I see a new climate study based upon a computer model, I feel like barfing. Computer models can only tell you an answer based upon what you have programmed the computer to perform. Research conducted in front of a computer screen. If you don’t have a sound theory and accurate observations/measurements, what can you prove? Where is the experiment? Where is the theory? Just as Lindzen stated: We have replaced theory and observations with computer models and simulations. The latter ain’t science.

  14. Neither of these two models are correct, imo, as they both misunderstand (or ignore) chaos theory. A system that exhibits chaos behaviour does not remain in a single state but constantly bifurcates, or cycles, through a sequence of states. Bifurcation was used in the article to describe the ‘seesaw’ model, but this is misleading because it implies that once the seesaw tips, it will remain in that state. This is not how a chaotic system behaviours.

    I believe that rather than requiring explanations of mysterious ‘forcings’, the earth’s natural climate variations are a near textbook example of chaos in action – the system moves from state to state. The important point is that under chaos theory, not forcings are required to cause these changing states. This may sound counter intuitive, but many lab experiments have shown these state changes taking place in various systems while the driver is held constant. Mandelbrot’s book on chaos is an excellent primer and offers numerous such examples.

    However, after all is said, this is an important line of inquiry, one that may eventually lead climate scientists to ‘bifurcate’ into a new state of understanding.

  15. For most of the last 650 million yeras the Earth has been warmer, or much warmer, than it is now. The present conditions are not the norm. The current ice age has been with us for the last couple of million years.

    This seems to be lacking a few facts to put it into correct perspective

  16. George E. Smith says: “. . . I don’t see how one could plan for some future unpredictable possibly dramatic event; the climatic result of which we cannot at this time forsee.”

    And yet they still pass the collection plate after services. What’s up with that?

  17. David , UK – I get the guesswork and arrogance , but I didn’t realize that there was fifteen million year ice old lying around .

  18. wayne says:
    August 30, 2010 at 9:14 am
    How do the day dreams of climatologists get published so easily?

    I have found recently that the daydreams of biologists are also published easily–if the so-called scientist has imagined a negative consequence of CO2 or global warming, or how something bad MIGHT occur. No evidence needed for these things to publish. Pro-wind-farm articles also publish easily, but thankfully, most other biological matters require actual science.

  19. Vince Causey says:
    August 30, 2010 at 9:39 am

    “However, after all is said, this is an important line of inquiry, one that may eventually lead climate scientists to ‘bifurcate’ into a new state of understanding.”

    Meanwhile, it can be used …
    “to keep the populace alarmed, and thus clamorous to be led to safety, by menacing it with an endless series of hobgoblins, all of them imaginary.”

  20. So the deniers have hijacked another journal? They must have a rotten peer-review! We should stop citing or publishing any papers in this journal!

  21. “””The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago, when the climate was very warm and alligators lived in England.”””

    Really? And where was England 15 million years ago? Think tectonics.

  22. Vince Causey says:
    August 30, 2010 at 9:39 am
    “Neither of these two models are correct, imo, as they both misunderstand (or ignore) chaos theory. A system that exhibits chaos behaviour does not remain in a single state but constantly bifurcates, or cycles, through a sequence of states. Bifurcation was used in the article to describe the ‘seesaw’ model, but this is misleading because it implies that once the seesaw tips, it will remain in that state. This is not how a chaotic system behaviours.

    I believe that rather than requiring explanations of mysterious ‘forcings’, the earth’s natural climate variations are a near textbook example of chaos in action – the system moves from state to state. […]”

    The earth’s climate over geological time never repeats exactly. Even the current climate cycling between glacials and interglacials doesn’t end each cycle with the climate winding up in the same place. I don’t understand how that can be modeled.

  23. Sun Spot says:
    August 30, 2010 at 9:24 am
    Regarding the “10-15,000 years of a warm climate like we have today” , where are we in this time period today ?

    Watch video clip and use comman sence.

  24. I don’t think we should sell this work short, at least until we can read the paper. I just hate pay walls. It seems to me that if one can not easily predict, due to chaos-dynamical fluctuations, when you know the result it would be impossible to precinct anything at all, if you don’t. Notice Ditlevsen did stress his research only deals with the past, not predictions of the future.

  25. I just walked three miles to drop off some completed engineering paperwork for auditing. There must have been a 10-15 degree temperature change since I got to work this morning. Must have reached a Global Warming Tipping Point!
    No wait…the sun came up and it got hotter. Maybe the sun had some thing to do with temperature changes in the past. Hmmmmmm.

  26. Oh no, another study, based…….on computer modelling! I’ve about reached my tipping point with such studies.

  27. I would also like to go on record to state that I also predict that the climate change that accrues within the forthcoming indeterminate time frame will in fact be of an unpredictable nature. Rather than a model involving a marble and two troughs, I prefer to conceptualize climate as a pea possibly found under any one of three inverted cups in an indeterminate changing sequence which model more closely resembles the state of climate modeling art.

  28. Dear Peter Ditlevsen,
    how come that the tipping point did not happen in the recent warmer past? It says the ice core, you know.

    How come that most of the last interglacial was warmer without those “unprecedented levels of CO2″?
    How long shall we listen to this BULLSHIT from government-paid academics?

  29. So, the climate’s temp could suddenly drop ten degrees with glaciers once again hitting the road south out of Canada …

    or

    The climate’s temp could suddenly rise ten degrees with summer sea ice and most glaciers vanishing and most of the temperate zone turning semi-tropical.

    Either way, the authors of this article can point to their study in triumph and declare that they told us so. And this is what passes for science these days?

    Reality check — mankind’s level of apprehension of climate science is at the level of a baby crawling; we’re working at it and trying to totter upright to try to make our first tottering steps, despite some claiming to be able to run a marathon.

  30. The noise induced scenario is a good one to do an FMEA on.

    I get a very high RPN. So, where are the contingency plans?

  31. H.R. says:
    August 30, 2010 at 10:41 am
    “The earth’s climate over geological time never repeats exactly. Even the current climate cycling between glacials and interglacials doesn’t end each cycle with the climate winding up in the same place. I don’t understand how that can be modeled.”

    It can be modeled. But a chaotic system is driven by its start parameters. A very small difference in the start parameters and the resultant system behavior can rapidly diverge from the previous iteration. The problem is that no-one knows the parameters that will affect the climate which is a chaotic system of chaotic systems and no-one knows the values of these parameters that will be important and no-one knows the critical states at which those parameter values will have their greatest impact. It may well be that at some states a parameter can vary wildly and have no effect whereas with the system in another state a tiny variance in that same parameter may lead to a large behavior change in the system. This is why looking for simple statistical correlations for ’cause and effect’ in a chaotic system is exhibiting ignorance of chaotic systems. A cause has to happen at the right time at the right level to have an effect.

  32. I don’t know why people here bash this study. As they say, they found out that small “chaos-dynamical fluctuations” suffice for a sudden regime shift. In other words, with or without CO2 concentration rises, there can be dramatic unpredictable changes; and current climate models cannot simulate this. For me, this is a very important step towards discarding the predictions made with current climate models.

  33. “The fear that global temperature can change very quickly and cause dramatic climate changes that may have a disastrous impact on many countries and populations is great around the world.”

    Frankly, no there is no great fear of sudden dramatic climate change. With the exception a minority of people all from the white middle class in the western world not many people are paying much attention, what with earning their daily bread and all. And in fact, the sudden change, the warmests themselves tell us, it really only weather. You need 30 plus years for weather patterns to morph into climate.

  34. “the ball is perhaps getting kicked more and could jump over into the other trench.”

    I think Peter Ditlevsen has perhaps misunderstood what the Dansgaard-Oeschger events are telling us. The “other” trench is a glacial period.

  35. We are so used to jumping down the throats of the authors of fiddled CAGW treatises by members of The Peer Review Back-slapping Society that we need to be more thoughtful about new climate science papers that are emerging from the climate dark ages. Folks, this is an interesting alternative to the throwaway science of the past 3 decades. It may not turn out to be a description of reality but I think it is a reasonable conjecture (among other alternatives) at this stage of the crawling-out. Their hat tip to CO2 is best seen as a timorous genuflexion that is necessary in the transition-to-science. Try not to be too mean!

  36. Sun Spot says:
    August 30, 2010 at 9:24 am

    Regarding the “10-15,000 years of a warm climate like we have today” , where are we in this time period today ?
    ___________________________________
    Here are two “peer reviewed” studies on that subject:
    Temperature and precipitation history of the Arctic

    “..Solar energy reached a summer maximum (9% higher than at present) ca 11 ka ago and has been decreasing since then, primarily in response to the precession of the equinoxes. The extra energy elevated early Holocene summer temperatures throughout the Arctic 1-3° C above 20th century averages, enough to completely melt many small glaciers throughout the Arctic, although the Greenland Ice Sheet was only slightly smaller than at present… As summer solar energy decreased in the second half of the Holocene, glaciers reestablished or advanced, sea ice expanded, and the flow of warm Atlantic water into the Arctic Ocean diminished. Late Holocene cooling reached its nadir during the Little Ice Age (about 1250-1850 AD), when sun-blocking volcanic eruptions and perhaps other causes added to the orbital cooling, allowing most Arctic glaciers to reach their maximum Holocene extent…”

    This paper also agrees that we are at the point in the earth’s Milankovitch cycle that should usher in an ice age. The biggest question of course is why we are not covered in ice yet.

    Lesson from the past: present insolation minimum holds potential for glacial inception (2007)

    “Because the intensities of the 397 ka BP and present insolation minima are very similar, we conclude that under natural boundary conditions the present insolation minimum holds the potential to terminate the Holocene interglacial. Our findings support the Ruddiman hypothesis [Ruddiman, W., 2003. The Anthropogenic Greenhouse Era began thousands of years ago. Climate Change 61, 261–293], which proposes that early anthropogenic greenhouse gas emission prevented the inception of a glacial that would otherwise already have started….”

    Here is an article similar to the one above by Woods Hole Oceanographic Institution
    Abrupt Climate Change: Should We Be Worried?

    “Most of the studies and debates on potential climate change, along with its ecological and economic impacts, have focused on the ongoing buildup of industrial greenhouse gases in the atmosphere and a gradual increase in global temperatures. This line of thinking, however, fails to consider another potentially disruptive climate scenario. It ignores recent and rapidly advancing evidence that Earth’s climate repeatedly has shifted abruptly and dramatically in the past, and is capable of doing so in the future.

    Fossil evidence clearly demonstrates that Earth vs climate can shift gears within a decade….

    But the concept remains little known and scarcely appreciated in the wider community of scientists, economists, policy makers, and world political and business leaders. Thus, world leaders may be planning for climate scenarios of global warming that are opposite to what might actually occur…

    And then there are “the ball kickers” The Forthcoming Grand Minimum of Solar Activity

    ”A method for predicting the next Grand Episode, based on previous results on the modes of oscillations in the solar dynamo (summarized in De Jager and Duhau, 2010) was introduced by de Jager and Duhau (2009). One of the results was the recognition of a transition from the Grand Maximum of the 20th century to another Grand Episode. This transition period started in 2000 and is expected to end in 2013.

    Based on the above mentioned methodology and by using new data for the geomagnetic aa index we foresee that a Grand Minimum is immanent. Thus, a prolonged period of relative global cooling is forecasted. The relevant mechanisms are described….”

    Joe Bastardi is saying both the AMO and PDO will be in the negative phase in 10 to 15 years, so all that will be left is the final trigger – a major volcanic eruption.

  37. Ian W says:
    August 30, 2010 at 12:04 pm
    (Ref. H.R. says:)
    August 30, 2010 at 10:41 am

    “It can be modeled. But a chaotic system is driven by its start parameters. [… omitted a very nice discussion of unknowns for brevity]”

    But as you point out, we don’t know all of the parameters and we don’t know the initial conditions. Also, even if we actually knew all of the parameters and the initial conditions, we still have to account for the random asteroid strike here and there. How and where does one put such events in a skilled climate model? (And anyway, who needs a climate model for an asteroid strike? You really don’t need a model for, “We’re screwed!”)

  38. P Walker says:
    August 30, 2010 at 9:10 am
    I’m going to regret asking this , but how does onr drtermine the makeup of the atmosphere from fifteen million years ago ? Accurately , that is .
    _________________________________________________

    If you are really interested in the other side of the CO2 analysis story look at http://www.co2web.info/

    Especially the pdf http://www.co2web.info/ESEF3VO2.pdf
    That pdf gives the politics and history behind the CO2 measurements. It is a real eye opener.

  39. If we simply take the warmest and the coldest periods from the past 2000 years and call everything in between “Climate Variation” we can dump the Climate Change where it belongs, in the dumpster together with all the other propaganda acts of the past century.
    It would be a great help because it would make the IPCC OBSOLETE and save us a huge amount of money.

  40. Warm future climate

    “But what about today – what can happen…? …the ball is perhaps … and could jump over … This could mean … theoretically could happen…”

    This idiotically dense thicket of subjunctive terms should be given a name – something like “dancing round the may-pole”.

  41. Seems to me that we are already on a warm plateau, so if that’s true, it’s the cold trench (moat) that awaits.

  42. Perhaps this might be called the “playground theory of climate”. With all the ups and downs, wild swings, and stuff being spewed here and there, and even with the big bully of climate – the Oceans, in the end, it is the Sun – the great Teacher in the Sky that calls the shots. Meanwhile, poor, barely-out-of diapers C02 stands cowering in a corner whimpering from time to time.

  43. Sun Spot says:
    August 30, 2010 at 9:24 am

    Regarding the “10-15,000 years of a warm climate like we have today” , where are we in this time period today ?

    Well the current interglacial started about 18,000 years ago (most common figure, study in Ireland reckons 19,000), so the glib answer would be “18,000 years in a 15,000 year period”.

    Actually, the whole measurement of “ice ages” seems to be a mess, with some people seeming to count the various Dryas events and the gaps between them as interstadials during a glaciation, and other people counting them as stadials during a interglacial period.

    The Younger Dryas (cold period) finished about 11,500 years ago, though there are persistant rumours that this may have been an impact event, and not due to climate cycles at all.

    In short – pick a number – any number…

  44. I had a quick read of that paper and I don’t think they are saying anything particularly remarkable. Chaotic systems cannot be predicted – they are their own fastest computer. The main issue of course is CO2 and whether it is a key parameter or a weak parameter in the global climate system. From everything I’ve read on WUWT and elsewhere, it seems to be an exceedingly weak parameter at best, uncorrelated with temperature. They don’t address this in the paper at all.

  45. Can’t really comment on the quality of this paper as full text isn’t freely available and I suspect the article is a dumbed down version for non-experts.

    Accurate prediction of future climate (100y+) is impossible due to the deterministic chaos which drives it. I suspect that both period doubling and several strange attractors are the cause of the quasi-cyclic oscillations we observe, and these are self similar at all temporal scales.

    Perhaps one day in the future we will develop the data gathering systems and knowledge to make some useful generalised climate forecasts, but the current state of climate science is a long way from achieving this.

    REPLY:
    see the update at bottom, full text provided – Anthony

  46. CO2 is not a culprit in any of these rapid climate changes.

    They cite 15 million years ago which was indeed 3C to 5C warmer than today but CO2 was only 200 ppm to 350 ppm for most of the time period (and as high as 450 ppm in one estimate at one interval).

    If the Dansgaard events (12 of them in the last 100,000 years including the Younger Dryas which was clearly just another of these same events which) shifted Greenland’s temperatures by +/-13.0C as has been surmised, then CO2 certainly wasn’t responsible since it changed only modestly (enough for +/- 0.5C or so at 3.0C per doubling).

    I don’t like these papers that operate through insinuation without showing the actual greenhouse effect implications of the data.

    What we do know is that there are 100,000 year ice ages which change global temperatures by -5.0C and there is some other variation of +/- 2.0C at other times in the last 40 million years (and there are some very large changes (-13C to -20C) in the Greenland ice core proxies in the ice ages – while the other North Atlantic proxies just show the smaller (-5.0C and +/-2.0C) global temperature changes).

    Again, the changes in CO2 over this entire time period going back 15 million years is only capable of explaining a very small part of the surmised temperature changes.

  47. RE: ‘The “other” trench is a glacial period.’

    Yep. Newsflash – the current NWS long range depicts a cold front slicing through Gerlach, NV, 1200 Z, Sunday 05-SEP. Things could be a bit “chaotic” for the partially to fully nekid Gaia worshippers out on “The Playa.”

  48. What is missing is a demonstration that the climate is indeed a system that jumps between states.

    Well that doesn’t need demonstration .
    Sin(t) “jumps” between states of +1 and – 1 .
    Chaotic pseudoperiodical oscilations “jump” between Max and Min states in the same sense .
    The only point being that a chaotic system doesn’t “jump” between only 2 states like suggested by the figure .
    If one considers that the climate evolves in a 5 dimensional phase space what several papers suggest then follows that every parameter oscilates chaotically between some Max and some Min .
    So there are then 5×2 = 10 different states and the climate jumps chaotically between them .
    Of course all this assumes that a “global” climate is a well defined system whose variables are spatial averages so that it depends only on time (and not space !) .
    This is almost certainly a wrong assumption .

  49. Simple people search for simple answers and tend to find simple and inexpensive solutions. Most simple people gravitate toward the simple and the inexpensive. A few simple people, who no doubt want to stand out in the crowd, espouse the simple and the expensive or, vary rarely, the complicated and the inexpensive.

    Complicated people search for complicated answers and tend to find complicated and expensive solutions. Most complicated people are never a real problem, they tend to come to the very complicated conclusion that the simple people won’t back them up and they generally move on to another complicated area or subject to study. A few complicated people, who no doubt want to stand out in the crowd, espouse the complicated and inexpensive or, very rarely, the simple and expensive.

    Most people are simple and inexpensive. Most politicians, economists, climatologists, and con-artists are very complicated and very, very expensive to simple people.

    PS: Sometimes the best answer regarding a complicated process is a very simple answer: We just don’t know. Yet!

  50. Well, plenty of dismissive comments, but this sort of description makes intuitive sense to me. Anyone who has worked with systems with multiple feedback mechanisms, both positive and negative, will recognise the same behaviour. It happens in complex electrical circuits, multi-component chemical reactions, ecosystems etc. Instead of a ball in a trench it’s more like a ball in a complex contoured landscape, like a badly made eggbox, or ski slope full of moguls. Applying some kind of forcing (which a 30% increase in CO2 is liable to do after all) will give the ball a push.

    Whether that will be enough to drop it into the next trough? I personally don’t think any modelling is sophisticated enough to predict that in such a massively interconnected system. But a bird’s eye view of the major trends (global temps, arctic ice, yada yada…) and a quick shave with Occam’s Razor would seem to say ‘probably’.

  51. “RE: TomVonk says:
    August 31, 2010 at 4:35 am
    If one considers that the climate evolves in a 5 dimensional phase space what several papers suggest then follows that every parameter oscilates chaotically between some Max and some Min .
    So there are then 5×2 = 10 different states and the climate jumps chaotically between them .”

    At the risk of being pedantic, that would be 2^5 different states – i.e. 32 possible stable climates. No wonder it fluctuates!

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