”Climate flicker” at the end of the last glacial period

From ETH in Zurich, this interesting essay on the last glacial period has some interesting points to ponder. h/t to Sid Stafford – Anthony

The last glacial period was characterised by strong climatic fluctuations. Scientists have now been able to prove very frequent and rapid climate change, particularly at the end of the Younger Dryas period, around 12,000 years ago. These fluctuations were accompanied by rapid changes in circulation in the oceans and the atmosphere.

Researchers are able to determine when glaciers were stable and when they melted by studying titanium content in glacial lake sediments. (Picture: siyublog/flickr)

Researchers are able to determine when glaciers were stable and when they melted by studying titanium content in glacial lake sediments. (Picture: siyublog/flickr)

Sediment deposits in lakes are the climate archives of the past. An international team of researchers from Norway, Switzerland and Germany have now examined sediments originating from the Younger Dryas period from the Kråkenes Lake in northwest Norway. In the sediments, they found clues that point to a “climate flicker” at the end of the last glacial period, oscillating between colder and warmer phases until the transition to the stable climate of the Holocene, our current interglacial period. The short-term, strong fluctuations of the Younger Dryas would have dwarfed the “extreme weather phenomena” seen today, according to Gerald Haug, professor at the Department for Earth Sciences at ETH Zürich and co-author of the study, which was published online yesterday in “Nature Geoscience”.

Seasonal sediment deposits

Seasonal sediment accumulation, for example, gave scientists clues to these strong climate fluctuations. They can be read in lakes in a similar way to reading rings on trees. In warmer phases and melting glaciers, the accumulation of sediments increases. More clues on the changes in glacier growth were given by the element titanium, which is present in the sediments. Glaciers erode their bedrock, and in doing so concentrate the titanium contained in the sediments they are carrying. The sediments containing titanium are washed into the glacier’s draining lakes in the meltwater. The amount of sediment and the titanium content can therefore allow us to deduce when the glaciers were stable and when they melted. The researchers interpreted the maxims, recurring every 10 years, as phases of strong glacier activity caused by temperature fluctuations and thus as warmer times.

A seemingly self-preserving cycle

The scientists also examined a sediment core from seabed deposits of the same age in the North Atlantic. They reconstructed the original temperature and salt concentration of the water based on microfossils and the oxygen isotope ratio in the sediment. It was shown that the results from the lake sediments corresponded to those from the sea sediments. “The melting of glaciers was caused by the warm Gulf stream advancing into this region,” Gerald Haug explains. This increase in temperature caused the west winds to shift to the north and brought warm air to northern Europe. However, the meltwater draining into the Atlantic lowered the salt concentration and the density of the surface water, changing the convection in the ocean, which in turn allowed new sea ice to form. Subsequently, the Gulf Stream and the west winds were again forced out of the North Atlantic area and the region cooled down once again. These processes were repeated for around 400 years, until the current interglacial period was able to stabilise itself.

The Würm glaciation began around 100,000 years ago and lasted until around 10,000 years ago. In this period, there were strong fluctuations between warm and cold phases, particularly in the North Atlantic area. The Younger Dryas, which ushered in the current interglacial period, is one of the best-known and best-researched abrupt climate changes of that glaciation. It began around 12,900 years ago and at first caused an abrupt temperature drop in the northern hemisphere, as well as a temperature rise of up to 10°C in less than 20 years towards the end, around 11,700 years ago.

Unclear mechanisms

Up until now, there have been several studies which document the glacial conditions during the Younger Dryas period of 1,200 years. However, the mechanisms which caused it, sustained it and finally led to an interglacial period have yet to be fully understood. The researchers believe that further high-resolution studies of this type could give insights into how glacial periods are triggered and how they are brought to an end.

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100 thoughts on “”Climate flicker” at the end of the last glacial period

  1. How interesting.

    What implications does this have for the theory of man-made global warming?

    If I read the article correctly, it would seem that the current climate changes which are being recorded are not, in fact, unprecedented at all.

  2. “They can be read in lakes in a similar way to reading rings on trees.”

    Right. Let discourse begin.

  3. The research supports what is quite well accepted by the scientific community about the transition at the end of the last glacial period and specifically the Younger Dryas event.

    See also

    http://www.ncdc.noaa.gov/paleo/abrupt/data4.html

    It certainly puts the last century’s <1C climate fluctuation into perspective, ie. it’s miniscule by comparison.

    And even IPCC reports accept that we don’t know what caused this and previous glacial-interglacial transitions – but you won’t find that admission unless you actually read the relevant chapters.

  4. A possible reason for the climate fluctuations considered herein may be the occasional rapid release of ice-margin-lakes. In North America these lakes stretched in an arc across the front of the melting continental glacier. Timing, outlets, and names varied.

    http://en.wikipedia.org/wiki/Lake_Agassiz

    And also here, under geologic history

    http://en.wikipedia.org/wiki/Mohawk_River

    This one uses the common term “pro-glacial lake.”
    The Straight of Juan de Fuca was also blocked with ice and a lake formed in Puget Sound. Then there are the Missoula Floods to consider. http://en.wikipedia.org/wiki/Missoula_Floods
    When flood waters went down the Mississippi into the Gulf there would have been temperature, density, and mixing going on.
    These episodes of the release of massive, fresh, ice-cold waters into the oceans are candidates for some of these “flickers.”

  5. It should be noted that the same “flickering” conditions are not seen in antarctic record. My guess is that ocean circulation patterns drive the ice age cycle, since they only started a few million years ago when the americas joined. The southern hemisphere being the engine and the north hemisphere is the overdrive!
    I also find it interesting that all glacial cycles have ended after a significant accumulation of dust in the antarctic ice, albedo reversal anyone?
    cheers

  6. Chris (21:42:09) :

    Other than the fact that the end of the Younger Dryas period has some pretty wild fluctuations which dwarfed the 20th century’s 0.6C/century climate warming, there’s not a whole lot in this to draw research that is applicable to our current climate conditions.

    What this research is leading towards is a better understanding of what happened between 12,900 and 11,700 years ago. With that understanding some clever geologist will hopefully be able to dream up an hypothesis of the physical causes which caused what happened.

  7. And to think that all this brouhaha is over a 1°C change over a period of a century. It pales in comparison to a 10°C change in 20 years time. People are so gullible.

  8. deadwood (23:43:41):

    I believe you miss an important point. Natural climate variability can be huge. It has happened in the past, it will happen in the future and, in fact, we should be getting close to a period where climate again becomes volatile as we are reaching the end of this interglacial if the duration of past interglacial periods is any indication.

    All of this recent fuss comes from some unfounded expectation that climate is stable. It isn’t. We are all in a panic over a 1 degree change over a period of 100 years. That is such a small amount of change that it gets lost in the noise of natural variability. The expectation that climate should be stable and that somehow humans can impact the global climate to a measurable degree is basically made up out of whole cloth. There are no actual observations that back it up.

    Yes, humans can impact the LOCAL climate to a great degree though modification of local environments through such things as deforestation, urban development, farming, and other land use changes but even with that, we impact only the part that is land. Part of what skews our vision of climate is that the observations we take are only on land and tend to be near developed areas. If one were to place a grid of buoys across the ocean, you would get a much clearer vision of what “global climate” actually is.

    Having a temperature recording device downwind of a major metroplex doesn’t measure “climate” any more than having one mounted on an iceberg would.

  9. “The researchers interpreted the maxims, recurring every 10 years, as phases of strong glacier activity caused by temperature fluctuations and thus as warmer times.”

    Now human beings have a natural tendency to round things to the number of digits on their hands.

    I would be fascinated to know whether they actually meant every 10 years, or every 11 years.

    Is the raw data available to allow a correlation with sun-spot cycles?

  10. studies of New Zealand Glaciers and histroical proxies for advances and retreats show frequent substantial advances and retreats as recorded by Prof Colin Burrows based on biological materials found, and published in a study of Von Haast’s work in the southern alps.
    rapid climate change was a common occurance on the last few thousand years.

  11. So, we have to give the traditional argument which is used for any previous climatic fluctuations. It goes like this.

    We start out asserting that climate has never fluctuated and so modern warming is unprecedented. We maintain this as long as we can, using Hockey Stick papers, pointing out that everyone who thinks different is funded by Exxon, even when they are not.

    However at some point we have to admit that younger Dryas or MWP or RWP really did happen. At that point we quickly reverse, and make the following argument.

    This, we say, actually strengthens our case, because it shows that climate sensitivity is greater than you the denialists realized. You should be more worried about CO2, not less, because the YD, MWP and RWP all show that tiny amounts of rise in temp will lead to catastrophic perturbations. Therefore we have to stop CO2 emissions now. As WorldWatch suggests, take them by 2050 to below the levels of 1850.

    So you see, we conclude triumphantly, you are screwed either way (that is a technical term of logic which you may not know, google it). If there was the natural variation you think, it shows todays warming is not unprecedented and you should be afraid and take action. If it was, well then obviously you should also be afraid and take action. Either way you must do what we suggest or die.

    All your climate are belong to us. Resistance is futile. Thank you for your attention.

  12. Surely the more they find that there are fluctuatations in temperature and ice extent greater than ours and within smaller time scales or similar ones. The less anybody will be able to conclude that carbon dioxide is the culprit. The more that this is the case the more emphasis will have to be given to other factors being responsible for climate variation that they are given not enough credence whilst carbon dioxide is seems the current flaw.
    singularly it is expected that the earth recovers from an ice age, recent MWP data only reinforces the analogy of cyclical climate. ie that climate would on recent data have fluctuated back anyway. ( It is the scale of these periods and others that were unrepresented or not talked about). tThe research above furthers the idea that change is predominantly natural. (and open to variation).

  13. I’ve always told people that if we can get to understand this temperature change of 10°C in 20 years, then I believe we will understand the true cause and effect of the current temperature fluctuations, aka climate change.

    It’s amazing how many people are not aware of this historical event and are genuinely shocked at the change. Education is the key!

  14. Over the Christmas holidays I re-read some of Jean Grove’s tome Little Ice
    Ages Ancient and Modern (second edition 2004). It is an outstanding
    instance of first rate scholarship. It is very detailed and very
    carefully reasoned with fascinating historical minutiae. A very
    satisfying read.

    One thing is striking.

    It is that during times of global warming there are periods of intense
    cold, sometimes for several years; and during the periods of global
    cooling there were warm stretches, also for several years. At the
    time, therefore, without the benefit of long time series and
    sophisticated analytic methodologies, you can’t tell what is
    happening. The time frames of the global events are in the hundreds
    of years. From the point of view of TC Mits (the celebrated man in
    the street), there is the experience of the last few years which might
    have been bitterly cold [or unseasonably warm], but now it is awfully
    hot [or freezing cold]. TC can’t see the pattern. TC is an
    existentialist!

    The point is, of course, that we can’t see a trend that might only be
    visible over time frames of hundreds of years.

    Based on the time series we have, we can see the warming that’s
    gradually been happening since the end of the little ice age around
    the 1850s. But even so, there’s been global cooling events and global
    warming events in that interval. Based on theories about the Sun and
    climate and the rotation of the earth and climate one can make
    something of a case for global cooling to come. These theories are, I
    would argue, vastly better than the IPCC/AWG ideas, but they are still
    rather speculative because there is so much we don’t understand and
    insufficient data.

    One of the fascinating vignettes of which Jean Groves gives excellent accounts is the attitude of the ecclesiastical authorities.

    The advance of glaciers begins to cause massive destruction of fields,
    live stock , villages, towns and great loss of life. There are
    devastating floods, all sorts of catastrophes.

    The clergy tells the people that this is God’s punishment for their
    sinful ways. Bishops and priests come -sometimes for substantial fees
    – to perform exorcisms to stop the glaciers and hopefully cause their
    retreat. If the exorcism didn’t work, this was because the people
    weren’t devoted enough: they did not have strong enough faith in the
    Bishop’s powers.

    The Bishop of Geneva had remarkable powers as his exorcism ’caused’ a
    terribly destructive glacier to stop and retreat in 1644 somewhere in
    France. Some 20 to 30 years later, he (by then a different human
    being: it was the role that gave him the powers) was called in by the
    people of Chamoix to stop a massive glacier destroying them. Once
    again the Bishop triumphed.

    Richard

  15. No No No, it’s not the oceans. It’s Man on land. After all the oceans and seas only account for a little more than 2/3rds of the Globe. Man on the other had has developed all the land, with the exception of the vast deserts, mountain ranges, the south pole, tundra areas and those large lake areas. I mean that must account for something like say, um, perhaps 10% of the remaining third that’s not oceans. So what is 10% of 30%?? Ok, maybe we’ve developed 20% of the landmass, that must be causing catastrophic boiling of the planet, right?!? That’s got to be a huge chunk of the planet, right?

  16. But surely, 10ºC in 20 years; that’s not climate, it’s just weather, ha ha.

    Could the Bishop of Geneva be persuaded to exorcise the AGW crowd?

  17. Large, abrupt climate changes do not occur only during glacial periods, though they are most common then.
    Google “8.2 KA event” or “preboreal oscillation” for two cases during the present interglacial and “Late Eemian Aridity Pulse” or “intra-eemian cold event” for two during the previous (Eemian) interglacial.

  18. Paul S (02:05:59) :

    “It’s amazing how many people are not aware of this historical event and are genuinely shocked at the change. Education is the key!”

    Well said – though I think many in the paleoclimate and geological community have perhaps been very aware of the complexity of the climate system for some time. I think a key issue is that they have typically been following the more traditional reserved, methodical, objective scientific method with no want to grab a soapbox (in my view that is what a scientist SHOULD do).

    Meanwhile, the crafty marketers and salesman with pseudo theories and dogmatic political and social views have astutely leveraged the pieces of “science” that fit their view of the world and have been allowed to command with ease with very loud voices from the soapbox/pulpit.

    Until the media and politicans learn to listen to objective science and not the guys with placards on the street corner claiming “the end is nigh”, the same problems will remain.

  19. RobJM (22:27:21) has made the salient point. These events are identified in the N hemispheric records (particularly high latitudes), whereas the S hemisphere response has been muted and on detailed inspection clearly responds in an antiphase manner with respect to changes in the N. hemisphere. This phenomenon has been increasingly well-charactierised and has got its own designation: “the bipolar see saw”.

    The evidence supports a scenario in which thresholds of meltwater from Northern ice sheets are periodically passed and the large dilution of the high latitude waters dilutes the salty surface waters of the Atlantic conveyer circulation, effectively and rapidly switching it off for a period. The high Northern latitudes cool abruptly while the reduced transfer of heat to the high Northern latitudes results in warming of the Southern oceans. In other words this is not a global warming/cooling phenomenon but is a massive and rapid change in the heat distribution of the Earth. The hemispheres respond in antiphase with a see-saw redistribution of heat due to large and rapid changes in ocean currents.

    rather topically, a paper that describes good evidence for this scenario was published yesterday in Nature:

    S. Barker et al (2009) Interhemispheric Atlantic seesaw response during the last deglaciation Nature 457, 1097-1102

    http://www.nature.com/nature/journal/v457/n7233/full/nature07770.html

  20. The finding that the climate has been very unstable in the past is hardly reassuring for assessing the current situation. Clearly, ocean currents are very important for global and region climates. It is not surprising that ocean currents can change on a relatively fast time scale and that they also can remain stable for long periods.

  21. I need to read this article. It seems to me this idea of previous rapid temp. fluctuations is a deal-breaker for the alarmists. Not only has there been much higher average temp. and CO2 in the past, but fluctuations have been just as rapid. The alarmists always say that the crisis lies in the rapidity of the change. If the T has changed so rapidly in the past, and there is still life on earth…no need for alarm. It will be interesting to see if someone can identify ecological effects of these historical rapid fluctuations.

  22. (Bill Green)

    I agree, “previous rapid temp. fluctuations is a deal-breaker for the alarmists”.

    10C change in 20 years is testament to that.

    12,000 years ago life on this planet survived many rapid fluctuations in climate over a 1200 year period. That robustness must be due to evolution, an inherent ability to adapt quickly to climate change.

    Mitigation as proposed by alarmists now runs counter to humanity’s own ability to adapt to and exploit climate change. Mitigation in this form can now be looked upon as simply a political and social tool to control our own natural behaviour.

    This study adds weight to the arguement that mitigation is likely to bring more human misery than adaption.

  23. There is plenty of evidence for rather drastic ecological effects of these abrupt climate changes, though mainly for the shifts to colder and drier climate. These include large-scale forest die-off, continental-scale dust-storms and abrupt disappearance of animals (including humans) from northern areas.

    Abrupt warmings are less visible, since it takes more time for animals and plants to react and invade newly suitable habitat, they show up best for very mobile animals like insects and birds.

  24. How does the “short primer” about CO2 fit in:

    …It began around 12,900 years ago and at first caused an abrupt temperature drop in the northern hemisphere, as well as a temperature rise of up to 10°C in less than 20 years towards the end, around 11,700 years ago…

  25. Thanks for the continuing investigation into rapid climate change and glaciation/interglacials. Bill Green wrote: “The alarmists always say that the crisis lies in the rapidity of the change. If the T has changed so rapidly in the past, and there is still life on earth…no need for alarm.” Two points here. 1. I think we all will be alarmed if the climate changes so quickly. 2. The AGWers will turn any new evidence to their purposes — IMO to reduce the wealth of developed nations. Evaporated affluence and the means for productivity (a drought of human causation) will make it ever more difficult to adapt to rapid climate change whenever those conditions arises.

    All my science publications seem to be part of the alarmist propaganda machine. I would like to know where this Nature article places that super-molecule CO2 in this skulduggery. Or, perhaps, some new alarmist entity will be added.

  26. Without putting up a link (Google will find stuff), the thinking about the Youger Dryas lately has been that it was “triggered” by a comet impact approximately around the western Great Lakes area, melting the glacier there enough to change the drainage toward the St Lawrence instead of the Mississippi. The cold period immediately after the impact was extended ~1000 yrs by the huge fresh-water pulse into the N Atlantic. This also coincides w/the period of N Amer extinctions.

    There is still arguments about the exact timing, tho.

  27. “What implications does this have for the theory of man-made global warming?”

    At a minimum, I would say this is circumstantial evidence that the warming we’ve seen is neither unprecedented in rate or magnitude. I expect it to be completely 100% dismissed by the strap-hangers over at ReallybadClimate.

  28. Is this “The Day after tomorrow II ?. It won´t happen anyway.
    Ceolfrith (22:44:30) :
    “Off Topic
    Someone had been reading too much Jules Verne” :Worst than that, perhaps reading Al-Qaeda´s Jihad .Please do not even dare to make such crazy experiments! What Dr Roger Angel (or Devil?) is proposing it is plain madness.

  29. Chris (21:42:09) :

    How interesting.

    What implications does this have for the theory of man-made global warming?

    If I read the article correctly, it would seem that the current climate changes which are being recorded are not, in fact, unprecedented at all.

    Bingo!

    People who know more about climate history seem to be less alarmed by recent changes. We can say with great certainty that climate has naturally changed rapidly in the past. The polar bear survived all the ups and downs.

    BTW: What’s the margin of error for measuring climate. How certain are we that observed changes over the last 100 years are outside the margin of error for measuring those changes?

  30. OT:
    Ceolfrith, it seems that that kind of thing may be the alarmists next step. Hurry up and create some massive project that they can then give credit to for the cooling. How else can they avoid being revealed as fools or worse?

  31. We shouldn’t be reading aricles like this and trying to make sense of phenomena such as climate “flicker”. The media, sponsored by a money trail as torturous as a rattlesnake’s winding path in the sand, is telling us that CO2, and by extension the common humanoid on the street, is factually responsible for all our ills. These articles should be burned. We only need the facts. Not the context, interpretations or meanings behind the facts.

    Fahrenheit_451

  32. Realitycheck,

    You make an interesting argument. However, if we know “the end is not nigh”, then there is no impetus to change the status quo. With no calamity in sight, there is no need for politician’s grandiose plans and massive influx of dollars for their sycophants, and thus civilization, as we know it collapses.

    Um, oh, I think I get it now. When AGW dies noisily, messily and painfully for all, a new and even more heinous event appears, thereby assuring full political employment for those so inclined to dine from the public trough.

    Sorry, I always was the slow one in school…

    Mike

  33. Gulf current is expected to be colder this year, what will cause less tropical storms of real magnitude as to be called hurricanes, but, as usual, these will be “properly” named. With La Nina and PDO around I am sure nobody sees a Gore´s scenarium of a Gulf current melting artic ice and changing sea water salinity.

  34. I like this statement:
    “The researchers believe that further high-resolution studies of this type could give insights into how glacial periods are triggered and how they are brought to an end.”

    It seems there’s an implication that we could trigger and end glacial periods at will. Hmmm….

  35. “It seems to me this idea of previous rapid temp. fluctuations is a deal-breaker for the alarmists”

    You would think so, but this is not how it works. The argument very seriously being offered is that previous rapid fluctuations are evidence for the alarming nature of the present warming. What was at first cited as alarming was the alleged unprecedentedness. The argument then was, this has never happened before, therefore it must be CO2 that causes it.

    Now that that argument looks like its in peril, because it has happened pretty often before, the argument being used goes: well, it doesn’t matter. It is not admitted that the Hockey Stick was wrong. But it is argued that if it was wrong, that strengthens the alarmist argument.

    If there have been previous fluctuations, this shows the climate is more susceptible to forcing that we thought, so this makes it more important, not less, to eliminate all forcing, and that means that even more, we should stop putting all that CO2 into the atmosphere.

    So either way, we got to be alarmed. Obviously unprecedented warming would be alarming. But so would precedented warming.

    I know, its nuts. But this really is how the argument is being run.

  36. Anthony
    I am sure that you are aware that ther have been a numbner of these flickers in the past, that is to say that there has been sudden and rapid climate change before. Dr Richard Alley, although a little bit on the warmers side has said on many occasions that sudden changes in climate can beed seen in the Greenland ice cores.
    One interesting study, back in the 70’s, by George Denton at University of Maine, showed that sudden changes occured as the last ice age approached.

    At 115,000 , 110,000, 90,000 and then several shallow changes around 70,000 yrs ago the planet cooled sharply. The 90,000 yr cooling was particularly fierce and sudden and lasted about 1000 yrs.

    When he looked at the last ice age these changes became more and more frequent until the plunge into full ice age about 40,000 yrs ago.

    So does climate change without man, yes. Does climate change gradually? Well there is little evidence that it does. Does it change suddenly? YES.

    Where are we now in the cycle of ice ages? We are approaching the years when sudden changes started to occur the last time. BUT remember, the human life time is miniscule in these time scales.

    And if one more idiot from the RC club mentions tipping point è-è-‘-è(è_))_;;;

  37. Yes, but since it has not been peer reviewed by the team, we can’t trust its results or its methods.

    [snip]

  38. It is entirely possible that the rapid changes at the end of the Younger Dryas period are the causation of the current oscillations that we now see in PDO, AMO, SOI, ENSO and MOUSE(LOL). Just a thought.

  39. A new paper in the Feb 27 issue of Science apparently implies that CO2 reduction led to lower temperatures and antarctic ice sheet development. I do not have a paid subscription so cannot verify. I can only read a description at

    http://www.physorg.com/news154883447.html

    This seems to contradict the temp-leads-CO2 idea.
    Could someone with a subscription have a look at the paper maybe to see what they are actually reporting?

  40. foinavon (03:42:15) Ice Age is not global cooling? So the 100 meter drop in sealevel was only in the northern hemisphere? 90% of 100,000 years is only “a period”?
    This climate change, as opposed to the weather change the IPCC has hung its hat on, has been well known for decades by anyone who has investigated paleo climate in the last 50 years. The fantasy of AGW is just a political power grab. We need to be figuring out how to survive without crops north of 30 degrees, short growing seasons, and if we can influence climate forcings that we don’t understand to prolong the point of termination of this interglacial which is imminent in climatic scales. We do not understand climate!!!!

  41. crosspatch (00:12:52) :

    I don’t dispute your comments regarding precedence, but I think research into the Younger Dryas is not particularly applicable to our current climate. We are not in any way (i>enjoying similar climatic conditions as were present then.

    beng (06:07:07) :

    I don’t know about comet impacts in the Great Lakes area, but I am aware of the hypothesis about rapid melting on the southern margin of the Laurentide ice sheet contributing the the Younger Dryas through disruption of the North Atlantic oceanic circulation. It looks as though the research highlighted above supports this hypothesis.

  42. This catastrophism is of psychiatric origin: “Level 1 Defense Mechanisms – Almost always pathological; for the user these three defenses permit someone to rearrange external reality (and therefore not have to cope with reality); for the beholder, the users of these mechanisms frequently appear crazy or insane. These are the “psychotic” defenses, common in overt psychosis, in dreams, and throughout childhood. They include:
    Denial – a refusal to accept external reality because it is too threatening. There are examples of denial being adaptive (for example, it might be adaptive for a person who is dying to have some denial.
    Distortion – a gross reshaping of external reality to meet internal needs Delusional Projection – frank delusions about external reality, usually of a persecutory nature ”
    Link: http://drsanity.blogspot.com/2004/08/psychiatry-101-defense-mechanisms.html

  43. Interesting that these events should have been witnessed by our ancestors.

    It would easily account for the wide spread stories of a universal flood found amongst 300 different cultures.

  44. Sitting here at 3201 feet in Missoula, I can see not less than 30 strandlines on Mt Sentinel to the east. These lines, reaching elevations of more than 4000 feet, are old Lake Missoula shorelines, created as the lake was repeatedly formed behind ice dams near what is now Lake Pend Oreille. These ice dams formed, failed and were reformed many times in the last 20,000 years of the most recent ice age. Would all that activity be correctly interpreted as a flicker? Haven’t seen a flicker like that since I put a nickel in an Edison machine.

  45. The ideas of temperature change leading CO2, ideas of global cooling, and stating that other planet temperatures are changing therefore that explains the Earth temperature change (dramatic increases since 1850), all of those are efforts to avoid taking responsibility for the health of the planet. We (humans) have greatly changed the CO2 concentration, and that change explains over 1 C temperature increase. The previous rapid temp. change in 20 years, if that is what we are indeed leading up to, is of no comfort. In our current, crowded world (think Asia) or environment-stressed world (think Africa) such changes would lead to catastrophic collapse in human population through starvation, war, and the rest of what happens when a species goes through the bust part of a boom/bust cycle.

    There are articles on the effect on just 1 C change in temperature – as others mentioned, major water current and wind shifts, amplifying the results. Shouldn’t we be reducing the risks of all this, even if it is not 100% sure? What is the cost? Fewer cars, more mass transit, focus on renewable energy sources, etc. My question is, why are some struggling so hard against making ANY change in their life habits, when there is at least a significant chance that the climate may change in very, very uncomfortable ways, and when there is the possibility we could take significant steps to reduce the risks. Last but not least: warming and climate change are not the only issue. There are growing fresh water shortages, greater difficulties getting oil, and other impending changes. These need to be considered with an objective and risk-reducing plan using the best minds available.

  46. Steve Keohane (08:03:06)

    foinavon (03:42:15) Ice Age is not global cooling? So the 100 meter drop in sealevel was only in the northern hemisphere? 90% of 100,000 years is only “a period”?

    You’re talking about something different there Steve. The see-saw transitions are rapid, transient asynchronous Nth/Sth cooling/warming events within glacials and on the glacial-interglacial transition. The global scale transitions from glacial-interglacial and back again are very, very slow processes which seem to be driven by very slow Earth orbital variations transmitted more extensively by ice sheet dynamics and greenhouse gas feedbacks. The “flickers” and the ice age periods are seperate issues (‘though there may be some overlap in mechanism..)

  47. crosspatch:

    If one were to place a grid of buoys across the ocean, you would get a much clearer vision of what “global climate” actually is.

    Just for any of the readers who are unaware, this has actually been done:

    http://www-argo.ucsd.edu/

    We don’t hear so much about Argo, for the simple fact that the REALITY it reports doesn’t much line up with the catastrophic predictions that are much more newsworthy.

  48. A.Syme (08:15:40) :

    Interesting that these events should have been witnessed by our ancestors.

    It would easily account for the wide spread stories of a universal flood found amongst 300 different cultures.

    Some believe a large comet plunged into the southern Indian Ocean off Madagascar a few thousand years ago. This would have cause massive tsunamis along the coasts and this may be the source of the flood stories.

  49. “Climate Flicker” is a very decriptive term. It modifies “abrupt climate change” and takes it’s place in helping to describe the continuum of changes of climate during the current ice age (2.5 million yrs), periods of glaciation (so far about 20), a like number of shorter periods of interglacial warming, and evidently also helps describe the transitions between sub-glaciations such as the younger dryas. Because of the way it is described, it appears to not apply to periods like the recent mini ice age, unless that could be considered a flicker event in a yet to be fully experienced multi-century timeframe that includes the present periods.

  50. Potentially OT,

    Is there room in this evidence line to consider signs of a large impact into a large ice formation related to the nano diamonds now identified in strata. Could the aftermath of such an event have caused a flicker?

  51. Codetech

    Ok I have now recovered a little… Having complained in the past about the deployment of so few weather stations to cover the earths land surface surely 3000 floats to cover the 70% of the earth that is water is not scientifically meaningful?

    Can anyone point me to a summary of what has been found out to date about sea temperatures in the various oceans?

    Tonyb

  52. Mary Hinge:”It has been a very strange year, the SOI has been around the 15 mark since September.”
    Weather conditions: Normal as expected …considering the recent Sun’s flicker- it flickers every 179,7 years- according to SIM enthusiasts: It changes from “trefoil pattern to quasi-trefoil pattern”, see: http://www.giurfa.com/charvatova.pdf

  53. jack mosevich (07:57:10)

    Jack that paper relates to the onset of the entire glacial period at the Eocene-Oligocene 34 million years ago. The idea is that weathering/mountain building over millions of years gradually reduced the CO2 concentrations below the thresholds that kept the Antarctic continent ice-free. The finding is that the gradual reduction in greenhouse gases determined elsewhere are associated with a drop in global temperature and the drop in temperature is associated eventually with the build up of Antarctic ice…

    So it’s a bit of a different circumstance than the glacial-interglacial-glacial transitions within the post Eocene-Oligocene transition glacial period in which we currently residue…

    here’s the abstract:

    http://www.sciencemag.org/cgi/content/abstract/323/5918/1187

  54. I am finding that the tree ring data for my area of the Earth (Pacific Northwest) was far more climactically stable during the Dalton Minimum than it is now.
    The Dalton made it look like an anchor.
    I’m all for another one.

  55. Actually that theory about a slow reduction of CO2 in the atmosphere causing the rather abrupt cooling in the early Oligocene (with the first continental ice-sheet in East Antarctica) is pretty shaky. Among other things it can’t explain why temperatures rose again after a fairly brief glaciation. As a matter of fact by the Late Oligocene temperatures were pretty much back to what they were before the Oi-1 glaciation.

  56. foinavon (08:45:37) I stand corrected, didn’t read closely enough, not enough coffee yet. These abrupt changes, since they are short term, must be defined as weather. It is interesting these short term changes are the same magnitude as the whole warming from glacial to inter-glacial. Goes to show how little we know about climate beyond WAGs.

  57. David / PlanetThoughts.org (08:39:04) : Shouldn’t we be reducing the risks of all this, even if it is not 100% sure?
    ————-

    So, really, what we need to do is embrace a world government system that will solve this problem only because of the seriousness of the imagined problems? What if I make up a different problem, throw some science in for good measure, and define problems that are 10x worse than a 6C rise in temp? Would you then be willing to do whatever I prescribe? You know – it’s all about the seriousness of the imagined concequences after all.

  58. David / PlanetThoughts.org (08:39:04) :

    The ideas of temperature change leading CO2, ideas of global cooling, and stating that other planet temperatures are changing therefore that explains the Earth temperature change (dramatic increases since 1850), all of those are efforts to avoid taking responsibility for the health of the planet.

    No, these are efforts to understand what is actually occurring.

    We (humans) have greatly changed the CO2 concentration, and that change explains over 1 C temperature increase. The previous rapid temp. change in 20 years, if that is what we are indeed leading up to, is of no comfort.

    Somewhat true, not demonstrably true, not all that rapid (certainly not unprecedented) and what is the reason to worry?

    In our current, crowded world (think Asia) or environment-stressed world (think Africa) such changes would lead to catastrophic collapse in human population through starvation, war, and the rest of what happens when a species goes through the bust part of a boom/bust cycle.

    Very unlikely. By studying past climate change, we know that most species, along with human civilization, adapted. Starvation, war, famine, plagues are prevalent during global cooling whereas global warming usually leads to milder weather and more food. Please look into the Little Ice Age and the Medieval Warm Period. In regards to climate, which would you rather have lived in?

    There are articles on the effect on just 1 C change in temperature – as others mentioned, major water current and wind shifts, amplifying the results. Shouldn’t we be reducing the risks of all this, even if it is not 100% sure? What is the cost? Fewer cars, more mass transit, focus on renewable energy sources, etc. My question is, why are some struggling so hard against making ANY change in their life habits, when there is at least a significant chance that the climate may change in very, very uncomfortable ways, and when there is the possibility we could take significant steps to reduce the risks.

    You start from several flawed premises. The first is that warming, if it returns, will lead to climate catastrophe. There is no actual evidence of this. Going back to the MWP, it was warmer than anything experienced in the 20th century and the polar bear, the penguin, the pika and civilization all flourished.

    The second flawed premise is the belief that the changes you mentioned will make a difference on a global scale. We can take all the automobiles off the streets of the USA and it won’t make any difference with the climate.

    Only global changes may make a difference in the global climate. Since it is a competitive disadvantage to use expensive alternate energy in place of inexpensive fossil fuels, you’re not likely to enact those changes globally except through force. (Last I heard, China is expanding its military, so good luck with that.)

    Last but not least: warming and climate change are not the only issue. There are growing fresh water shortages, greater difficulties getting oil, and other impending changes. These need to be considered with an objective and risk-reducing plan using the best minds available.

    Lack of water is primarily a local problem. It can be solved through technology that is widely available today and through smarter use of current resources.

    The known oil reserves are many times the amount of all the oil consumed in the last 100 years. There will be plenty of oil to go around for decades and as we consume it, prices will increase and other energy sources will become economically viable.

    This is all the more reason to focus on real problems instead of attempting to control a necessary trace gas. Starvation is a problem in many parts of the world. So is high infant mortality. One way to help people with these problems and the other problems you mention is economic development.

  59. Let’s not overlook a very obvious implication of these paleo-data.

    Yes, the climate has changed (a lot) in the past and some of those changes have been very abrupt.

    But the system has ALWAYS reverted to a long-term general trend. NO TIPPING POINTS, NO RUNAWAY CALAMITIES.

    Once you realize that, the squabbling over cause vs effect is just that.

    The only thing unprecedented about climate change today is that 6.5 Bn people are watching it.

  60. John Galt “This is all the more reason to focus on real problems instead of attempting to control a necessary trace gas” Wise words. All the rest is plainly insanity.

  61. Steve Kehane:

    The Younger Dryas lasted about 800 years, thats pretty long for “weather”. And Foinavon: glacial/interglacial shifts are not “very slow”. They occur stepwise and are quite abrupt, at least on a geological time-scale.

  62. RE: Richard Mackey (02:17:30) :

    Fascinating thought, about the use of weather/climate by the authorities to manipulate the ignorant. From the beginning of civilization and beyond, people have tirelessly watched the stars, moon and sun, meticulously recording their positions in the sky. What if some ancient government was able to deduce vague correlatations, say, between the number of sunspots in a given year, and the local temperatures and weather patterns that follow. As long as you can somewhat predict the weather, you could trick the ignorant into believing that you can control the weather. That makes you a god to the gullible (or Gore-ible)

  63. Bill Green (04:28:31)

    You wrote: “It will be interesting to see if someone can identify ecological effects of these historical rapid fluctuations.”

    Usually under the heading of “refuge areas” or some such title.
    Here are two: http://www.jstor.org/pss/2413377

    http://www3.interscience.wiley.com/journal/119411457/abstract

    I don’t have the reference but the Great Smoky Mountains were reported to be a refuge for more northern species during the last ice age.

    Also, try this: http://co2science.org/subject/i/summaries/butterflies.php

  64. Regarding:

    “John Galt (10:58:02) :”

    and his respone to “David / PlanetThoughts.org (08:39:04) :”

    John, your response was point by point perfect!

    David,

    The best way to solve the problems that you address is by implementing the free market system across the globe. I know what you are thinking, but stay with me.
    The free market system allows for a standard of wealth that can afford the environmental outcomes that you wish for; economies whose decisions are based on environment fear mongoring won’t supply the money to pay for what you want accomplished. For the short term, we are going to have to rely on hydrocarbon fuels and an expanded nuclear power generation system.

    In the long run, the wealth that is created by “capitalism” can be tapped to cure malaria, AIDs, poverty, lack of education, birth control, and pollution caused by the ineficient use of all carbon based fuels (that was a short list of our problems, I know there are more problems).

    Scare tactics based on “feelings” and not based on sound science, history, geology, engineering, and physics won’t solve mankinds problems. In order to fund the above activities, a sound economy conducted by people endowed with freedom is required.

  65. There are growing fresh water shortages,

    There are growing local fresh water shortages. Due to the failure of mostly governments to invest in adequate infrastructure for at least the last 50 years and politicization of water ownership rights.

    To imply this is somehow unsolvable and inevitable is ridiculous. You might as well argue your local KMart has a growing shortage of plasma TVs.

    All economic activity is in response to a shortage of something, somewhere.

    Treat water like any other tradeable commodity and local shortages will be solved in fairly short order.

  66. @RobJM (22:27:21) :

    “It should be noted that the same “flickering” conditions are not seen in antarctic record. My guess is that ocean circulation patterns drive the ice age cycle, since they only started a few million years ago when the americas joined. The southern hemisphere being the engine and the north hemisphere is the overdrive!”

    Amen. I’m a true believer in your church. But the glacials and interglacials are still just weather when you consider the climate history of the earth.

    “I also find it interesting that all glacial cycles have ended after a significant accumulation of dust in the antarctic ice, albedo reversal anyone?
    cheers”

    I wasn’t aware of that. Sources, please? I’d really like to know. I will either shout out another amen or consider joining another church, depending on what you provide ;o)

    P.S. Are you a geologist?

  67. @fred (07:30:26) :

    From the peanut gallery: I’ve pondered what you’ve written and you’ve nailed it.

    Class? Class? Required reading, everyone. (Can I get an “Amen” from crosspatch and Smokey?)

  68. ABRUPT CLIMATE AND SEA LEVEL CHANGES DURING THE LAST MILLENNIUM

    There is an abundance of evidence of abrupt climate and sea level changes over the last millennium, additional to Jean Grove’s massive and thorough research.

    Here’s another example, one only has to listen carefully to what the tube worms are trying to tell us, now read on….

    BAKER et al (2005) used evidence of tubeworms to find evidence about sea level changes. The tubeworms attach themselves to coastal rocks at inter-tidal levels, as they have to be covered by seawater for about six hours each day. The careful study of tubeworm casings along coastlines in Australia, Brazil and South-east Asia has revealed that, even within the past thousand years, there have been several sudden changes in sea levels of up to two metres.

    The UNE team has discovered that each of these large changes took less than 40 years from beginning to end. They have therefore found convincing evidence of large, rapid changes in sea levels around the world in the recent past.

    ‘Most of the climate-change modelling done in Australia and overseas assumes a basically stable natural system underlying the man-made variable of greenhouse gases,’ said one of the UNE researchers, Dr Robert Baker. ‘Our research indicates that the underlying system is anything but stable and that we would be well advised to take this into consideration in our planning. We’re adding a destabilising factor (greenhouse gases) to a system that is already subject to large, rapid changes.’ (See National Science Week article dated August 19 2005 Sea level changes give us an urgent message on the website of the University of New England: http://www.une.edu.au/news/archives/000327.html )

    BAKER et al (2005) were collaborating on the project for the past eight years and have published nine papers in scientific journals in relation to it.

    BAKER et al (2005) builds on research Professor Fairbridge conducted on Rottnest Island off Perth in the late 1940s and published in 1950. This research was the basis for his pioneering theory of the Fairbridge curve.

    Reference:
    BAKER, R. G. V., HAWORTH, J., FLOOD, P. G., (2005). An oscillating Holocene sea-level? Revisiting Rottnest Island, Western Australia, and the Fairbridge Eustatic Hypothesis. Journal of Coastal Research, SI42, 3-14

    Rhodes Fairbridge was the first to document that the ocean levels rose and fell over long time scales. His first paper on this theme was published in 1950 (FAIRBRIDGE, 1950). The major paper that included what has become known as the Fairbridge Curve of the Holocene Eustatic Fluctuations was published in 1958 (FAIRBRIDGE, 1958, 1960, 1961a).

    These are extracts from a paper of mine wherein you can find all the other references:

    http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf

  69. Richard Mackey (19:37:12)

    BAKER, R. G. V., HAWORTH, J., FLOOD, P. G., (2005). An oscillating Holocene sea-level? Revisiting Rottnest Island, Western Australia, and the Fairbridge Eustatic Hypothesis. Journal of Coastal Research, SI42, 3-14

    I can’t find this paper via the web, JSTOR, or from the Journal archive, although it’s often been cited.

    Could you post a PDF?

    Thanks.

  70. tty (11:52:05) 10 deg C in 20 years, as the article claims, is weather. I saw this information a year or two ago, and am glad to revisit it regarding the discernment of weather vs. climate. I had originally agreed with the line of thought that decades of weather=climate. However, in consideration of the multi-decadal ocean oscillations, I had come to think we need 120-150 years of consistant measurements to discern a trend in climate over weather. If, as the above article states that we can have 10 deg C increases in 20 years, this is the same magnitude of the whole temperature rise coming from glaciation to maximum temperatures in the interglacial, then weather has the same magnitude as climate, and we need 2-3 centuries of measurements to tell if it is indeed climate. Let me know c. 2230 AD, and we’ll look at the data to see if the climate has changed. As a side note, whatever can change the global temperature 10 deg C in 20 years makes CO2 look like a feather compared to an atom bomb, not scarey or anything to be concerned about.
    I was in my 20s in the 70s and while there is no such thing as consensus in science, so Connolly is correct that there was not, the general thinking was that an ice age is coming.

  71. Steve Keohane 061308
    …”we need 2-3 centuries of measurements to tell if it is indeed climate.”

    I concur. When can we get started with these measurements?

  72. Along with gradual revision of atmospheric processes in GCM, feedbacks etc, I’d guess paleodata too will need to be revisited as to interpretation, role of CO2 etc – where else would such understanding come from?

  73. ”we need 2-3 centuries of measurements to tell if it is indeed climate.”

    That is also the lesson taught to us by the efforts to allocate stream flows based on 30 year average precipitation. Proper allocation of available historical stream flow over 30 years will leave some water claims unsatisfied in a subsequent 30 year cycle.

    This is one of the reasons California is having water supply problems, she has been using more then her allocation of water for Colorado river water for some time. It was not a problem when Arizona and Nevada did not use their full claim, but as the upstream states begin to claim more of their allowed water usage California is getting left short. The Colorado River compact was drawn up in 1922 with water usage limits predicated on what they believed to be reasonably expected average flow of the river system. Over the years it has been found that the total flow in the river system has a wider swing than they anticipated, and growth has also exceeded expectations. Precipitation like temperature can vary over wide ranges over century time spans as the Anasazi found out.

    http://wwa.colorado.edu/colorado_river/docs/CO%20River%20Compact.pdf

    http://wwa.colorado.edu/colorado_river/docs/pontius%20colorado.pdf

    The wettest 10-year period on record (1914 to 1923)
    saw an average annual flow of 18.8 maf. This period is especially significant because the Colorado River Compact, which allocated the river’s water, was
    negotiated in 1922. Since 1922, estimates of the river’s average flow have been
    consistently revised downward.

    We have already learned that short time span averages are inadequate for water management, it should not be surprising that similar short time spans do not get the job done when talking about temperature or sea level trends either.

    Larry

  74. MikeT (04:55:15) 28/02/09:
    Re a pdf of the tube worm paper by Baker et al.

    It’s Sunday evening down here in the land of Oz. I’ll be in the office during the week and will do my best. I have the journal so it shouldn’t be too hard!!

    Richard

  75. Regarding the point raised by Larry (hotrod (18:01:07) 28/02/09).

    This is the general thesis about the appropriate means of statistical analysis to use, given the properties of the geophysical time series.

    I refer readers to the homepage of Demetris Koutsoyiannis who has got across this problem probably better than anyone else in the world (see http://www.itia.ntua.gr/dk/).

    There is a month of Sundays of hard work to understand properly the remarkable scholarship listed there.

    Also Demetris’ pioneering breakthoughs have been recognised by his peers: he is awarded the Henry Darcy Medal for Hydrological Sciences at the forthcoming EGU2009 in Vienna.

    Read the Abstract of his lecture here:

    http://meetingorganizer.copernicus.org/EGU2009/EGU2009-14033.pdf

    It promises some very exciting intellectual breakthroughs central to the issue under discussion here, indeed central to our understanding of geophysical time series (of which climate time series are a subset) and economic and finacial time series such as those that tried to tell us of the impending GFC but “we” (ie the government and financial sector orthodox econmetric analysts weren’t using the right tools so we couldn’t hear the screams of warning.
    Richard

  76. My pet theory is that the flickers are due to the asymmetry in the formation and melting of ice. The formation is gradual, the melting is catastrophic. So at the end of an ice age, warm currents gouge out oceans of frozen ice and move them round, causing rapid climate change. In the depths of an ice age, the formation is more gradual and the swings are much smaller.

  77. ******
    Barry L. (10:29:11) :
    Younger Dryas was NOT caused by a comet impact!!!!!!!
    Select the PDF in the page.

    http://starburstfound.org/YDextinct/p1.html

    ******

    Well that’s a far-out theory. A supergalactic wave? Huge CMEs from the sun reaching the earth’s surface causing firestorms?

    Very interesting at least. It does explain the lack of craters. Kinda scary to think that galactic “weather” could cause that kind of havoc so recently.

  78. Richard Mackey (2:55 1/3) suggested reading the work of Demetris Koutsoyiannis (thanks), who writes: “Data also offer the only solid grounds to test any hypothesis about the dynamics, and failure of performing such testing against evidence from data renders the hypothesised dynamics worthless.” One of the most important purposes of WUWT is to make certain that the data used for hypothesizing about “climate change” is the most accurate possible.

    I am becoming concerned about the data for hypothesizing about “abrupt climate change” or even “flickers”. (I have been reading abstracts of a number of recent studies.) How is the data being gathered and for what purposes? Is this topic coming more to the forefront today in order to scare us further about “tipping points” due to the combination (now it’s usually a combination) of forcing elements that always include CO2?

    Will the 2009 International Conference on Climate Change March 8-10 begin a list of vetted data gatherers (in addition to the presenters), and scientists whose research is based on valid data, and organizations who only work with valid data or who rush to correct theirs when problems are found? Our universities can no longer be trusted nor can our government scientists. IMO this is an important function for the only independent and investigative center in our society — serious bloggers.

  79. Pyromancer

    These are not tipping point, per se. All systems are inherently unstable unless they have some stabilisers built in (feedback). You will have heard sound systems that suddenly scream a very loud monotonic sound normally due to positive feedback from microphone to speaker and back again and so on. This is positive feedback. You may have seen someone adjust the volume so as to eliminate this whistle, that is reducing the positive feedback. Thge point at which it begins to screech could be termed a tipping point. In all large systems this is usually the end game and the system runs away to destruction. Chenobyl was a classic example. The carbon rods were designed to block the neutrons which were the positive feedback to the nuclear reaction but they failed to bring enough blocking to restrain the neutrons and voilà disaster ensued.

    There is little evidence for these dramatically rapid tipping points in our climate system, not because they don’t exist because they almost certainly do, but because in 3000,000,000 years climate change had been within nomminally reasonable bounds in spite of some massive changes caused by asteroids etc. That is, we have much the same climate now as we probably had some 10,000,000 yrs ago. The climate has swung between ice ages and period of greater warmth than now and the climate of now is not the climate that can be said to be NORMAL but never the less you have to admit that it is fairly stable +/- 0.5 °C in 150 yrs considerable humankind’ nasty habits.

    Ergo, somewhere in this massive system there has to be a good balance between negative and positive feedback which cannot be easily tipped either way very easily. Remember, in the last 250 yrs there have been some pretty big volcanic eruptions which temporarily modified the climate but the climate always returned to it’s previous state. This in itself is good evidence for some sizeable negative feedback(s).

  80. Along with gradual revision of atmospheric processes in GCM, feedbacks etc, I’d guess paleodata too will need to be revisited as to interpretation, role of CO2 etc – where else would such understanding come from? yes

  81. MikeT (04:55:15) 28/02/09: Re a pdf of the tube worm paper by Baker et al.

    I now have a pdf made from scanning the journal article

    I can’t work out how to attach it here.

    I’ve emailed it to Anthony to either post on WUWT or to email you directly.

    Richard

  82. Richard Mackey (19:33:51) :

    Thanks Richard, that’s very kind of you. Much appreciated.

    And if Anthony finds the time to send it through/post it up, also much appreciated!

    The use of invertebrates/invertebrate structures for this kind of analysis is fascinating (to me, at least!).

    Many thanks

    Mike

  83. Steve Keohane (08:03:06) : We need to be figuring out how to survive without crops north of 30 degrees, short growing seasons, and if we can influence climate forcings that we don’t understand to prolong the point of termination of this interglacial which is imminent in climatic scales.

    Well, I’ve got some good news and I’ve got some bad news ;-)

    There will be crops north of 30, just mostly on the West Coast. Short growing seasons are not so hard. There are many short season varieties developed specifically for cold northern climates. For any given latitude, you can also just grow a slightly more cold tolerant crop (i.e. Kale instead of Chard or Potato instead of Wheat). And if you are willing to put together cloches or greenhouses, there is no limit.

    Per the “imminent” ice ages: WHEN it starts (that could be up to 10,000s of years in the future, but also could have been back in the LIA) it will proceed slowly. I figured it out at about an 800 foot per year rate of ice advance… It will be very hard to know when it has happened because we are about 3 or 4 orders of magnitude off in our sense of time vs glacial time.

    Mitigation? Probably not so hard. One solution I saw proposed was to just widen the Panama canal to a few miles with “Atoms for Peace” excavation and restore the current that used to keep them away. Another would be to just make lots and lots of Freon again… and there are always the space mirror concepts. Personally, I’d just by a Polaris snowmobile…

    Bottom line is that if a brand new Ice Age Glacial Period had started 200 years ago, we would know for sure in about 2000 years. Nuclear power is effectively unlimited, and with that you can have unlimited greenhouse foods and heat. So we might all end up living in Brazil in condo’s. I’m good with that ;-)

  84. Anthony: if you’re still tuned in to this thread, I’ve made contact with Richard Mackey and have the PDF he sent to you.

    Thanks!

  85. The Younger Dryas lasted about 800 years, thats pretty long for “weather”. And Foinavon: glacial/interglacial shifts are not “very slow”. They occur stepwise and are quite abrupt, at least on a geological time-scale.

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