Pliocene Warm Period 3 C Warmer Than Today

Interesting what you find sometimes when you start riding a Google Train. One thing leads to another and then you find out that in the prior interglacials it was WARMER than today. All Natural.

While we saw some of that in the Florida Rising posting, this posting looks at new work done on Bering Sea sediments. From 4 to 5 Million years back, not just a few hundred thousand.

Pliocene Sea Surface Was Hotter Than Now.  Anomaly in C.

Pliocene Sea Surface Was Hotter Than Now. Anomaly in C.

Original Image.

Data source:

Which page is riddled with AGW Double Speak. A favored bit?

Scientists have identified many primary forcing mechanisms that contribute to the current global warming, but there is uncertainty about the relative impact of each forcing and associated feedbacks. The mid- Piacenzian presents the reverse situation: global data sets reveal the mature state of a warmer world, but the forcings that led to Pliocene warming are only partially identified. The data so far compiled by the Pliocene Research, Interpretation and Synoptic Mapping group (PRISM) suggest a combination of increased greenhouse gases and increased ocean heat transport acted concurrently through undetermined feedback relationships.

So it happened all by itself in the past, and we have little clue why, but “This time it’s different and MUST be because of us”. Yeah, right.

How about this one instead: Natural changes in ocean currents and solar output caused a warming cycle that liberated a load of CO2 from the oceans (which showed up with an 800 year lag after the warming as the deep ocean water turned over). That’s how I’d expect it to work. So what were the conditions then?

From this article:

Bering Sea was ice-free and full of life during last warm period, study finds

December 13, 2010 By Donna Hesterman

UCSC ocean scientist Christina Ravelo and Alan Mix of Oregon State University show off a record-breaking sediment core section during the Bering Sea expedition. Ravelo (below) was co-chief scientist of the expedition on the RV Joides Resolution. Photo credit: Carlos Alvarez Zarikian, IODP/TAMU.

Deep sediment cores retrieved from the Bering Sea floor indicate that the region was ice-free all year and biological productivity was high during the last major warm period in Earth’s climate history.

Gee. It was a lot warmer then. “Biological productivity” was higher. As in “more food” and “easier living”…

And it was all natural

The researchers drilled down 700 meters through rock and sludge to retrieve sediments deposited during the Pliocene Warm Period, 3.5 to 4.5 million years ago.

“Evidence from the Pliocene Warm Period is relevant to studies of current climate change because it was the last time in our Earth’s history when global temperatures were higher than today,” Ravelo said.

Carbon dioxide levels during the Pliocene Warm Period were also comparable to levels today, and average temperatures were a few degrees higher,

I’m sure the Warmistas will try to spin this that the CO2 caused the warming, but who was burning all the oil and driving SUVs then? Hmmm? Oh, and there is the little problem of the 800 year lag between warming and when the CO2 shows up…

So to me it’s pretty dramatic confirmation that CO2 levels NATURALLY were higher at the same time it NATURALLY was warmer; and the warmth drove the CO2 out of the ocean just as the gas laws predict.

And it all happened with NO human intervention as the only “people” around then were more like smart chimpanzees than modern humans.

Current observations show more rapid warming in the Arctic compared to other places on Earth and compared to what was expected based on global climate models.

Ravelo’s team found evidence of similar amplified warming at the poles during the Pliocene Warm Period. Analysis of the sediment samples indicated that average sea surface temperatures in the Bering Sea were at least 5 degrees Celsius warmer than today, while average global temperatures were only 3 degrees warmer than today.

Gee, and the Arctic was a whole lot hotter than now. So the hotter Arctic now is caused by us but the hotter Arctic then was caused by nature? But the good news is that with a 5 C hotter Arctic, we didn’t hit any “tipping point”. We have an “existence proof” now that it doesn’t exist.

Samples from the expedition showed evidence of consistently high biological productivity in the Bering Sea throughout the past five million years.

This I find quite fascinating. They don’t say much about when the higher productivity stopped. But “throughout the past five million years” says it had to be “recently” on a geological time scale. Something has changed about the North Pacific water flow.

In addition, samples from the Pliocene Warm Period include deep-water organisms that require more oxygenated conditions than exist today, suggesting that the mixing of water layers in the Bering Sea was greater than it is now, Ravelo said.

“We usually think of the ocean as being more stratified during warm periods, with less vertical movement in the water column,” she said. “If the ocean was actually overturning more during a period when it was warmer than today, then we may need to change our thinking about ocean circulation.”

Well, so much for yet more “Settle Science”. If we “need to change our thinking about ocean circulation” we don’t know diddly about what makes this system work. Looks like we can put to bed all the paranoid fantasies about stagnation and stratification of the ocean as well. Oh, and the “acidification” of the ocean arguments. Since we have had similar high CO2; and everything, well, lived (and lived well from the looks of it) that whole “ocean can’t take it” angle is toast. Can you say “Existence Proof”? I knew you could…

Today, the Bering Sea is ice-free only during the summer, but the sediment samples indicate it was ice-free year-round during the Pliocene Warm Period. According to Ravelo, the samples showed no evidence of the pebbles and other debris that ice floes carry from the land out to sea and deposit on the seafloor as they melt. In addition, the researchers didn’t find any of the microorganisms typically associated with sea ice, she said.

Well, so much for the idea that if we lose the Arctic Ice Cap all hell breaks lose and that we’ve never had the North Pole ice free. It was hotter. There was no ice. Then it got colder and we went back into the subsequent Glacial period.

Some Background

I’ve not used this particular graph before. I usually start with the second graph that shows the history of the most recent ice ages. But since this story is about times further back in history, a bit more context will be in order.

5 Million Years of Global Cooling and Change

5 Million Years of Global Cooling and Change

Original Image

OK, the time we’re talking about is back about that 4 Million Years Before Present point (MYBP).

Look at the chart for a moment. Notice the trend. From upper left to lower right. Cooling. Think about it.

Notice that about 2.5 MYBP to 1 MYBP we used to pop up to warmer about every 41,000 years and had less extreme cycles. Now it’s only about every 100,000 years. As were getting steadily colder, we’re also slowing down the rate of cycles and the frequency with which we have a brief warm period. Again, think about it…

Now look at that period between about 3 MYBP and 5.25 MYBP. It was fairly uniformly within 2 C of, well, right now. The “natural state” for the last 2.5 MY has been Ice Ages. Most of Europe, Asia, and North America under glacial ice. Brief visits to our present world of green and warm. Then a plunge back into the freezer. The only “tipping point” is to the downside. To freezing. That first couple of million years says so. Warmer than now and things just steady out and dampen. Colder and things go unstable with wider ranges to the downside. Think about it some more.

So, if we tried Really Really hard, and managed to create horrible global warming with scads of CO2 just like back in the 5 MYBP Pliocene, it MIGHT get 2 C warmer. And basically the world would stay about like it is now. If it cools off just a bit, we plunge back into an Ice Age Glacial at 8 C to 10 C colder than now as a global average.

OK, got that context?

Here’s that last bit blown up larger so you can see each of those little peaks spread out to 100,000 year saw tooth shaped events.

Recent Ice Age Glacials - 2 Antarctic Ice Cores and Ice Volume

Recent Ice Age Glacials - 2 Antarctic Ice Cores and Ice Volume

We’ve seen this one before, but just as a reminder, the ice is “upside down” so a “peak” is when there is no ice during an interglacial. Most of the time the ice volume is very large (the curve is below the dotted line by a lot).

Notice that the prior “Interglacial warm spikes” have been higher than this one. Warmer. We didn’t spike as high, but we’re spreading it out a bit more; about the same interval of time as the other spikes had above the dotted line, just we’re staying closer to “smack on” that line. Next stop, however, is down.

In Conclusion

It looks to me like we have absolutely nothing to fear from a warmer world. The world has been there before, even as recently as 120,000 years ago. It stayed there for several millions of years during the years that formed our species (and during the time that most species on this planet developed – they have nothing to fear from a warmer world either). But over the last 5 million years the climate has become more unstable and volatile due to our consistent cooling trend.

The recent interglacials all show us that this present warm time will not last. We’re near the end as it is. They also show us that it’s a rapid ride down to cold, then 80,000 years or so of accumulating ice and increasing dustiness. Dust? Yeah, dust:

(Note that time runs “the other way” in this graph. “Now” is on the left.)

Vostok Ice Core Dust, Temperatures, CO2

Vostok Ice Core Dust, Temperatures, CO2

Each warm spike ends with a plunge to cold, then a partial recovery from the overshoot, back onto the sawtooth pattern down. And the added cold starts washing the CO2 out of the air, back into ices and cold oceans. (CO2 dissolves much better in cold water – a known gas law.)

Look at those low CO2 levels. Below 200 PPM plants basically suffocate. Productivity drops dramatically. Cold oceans don’t evaporate well, and extreme polar cold sucks moisture from the air to make those giant glacier sheets. Which grow steadily until the glacial ends. I would also note that with each cycle the dust has gotten worse (it’s a harder drought) and the ‘high ice period’ is longer. We gain ice faster and sit ‘fully frozen’ a bit longer. The ice age glacials are each just a little worse than the last.

An Ice Age Glacial is a cold, dead, dry, dusty desert place.

So, we have a warm, pleasant, stable, life filled world when it’s warm, or a volatile, hostile, cold, dry, dead, dusty desert when it’s cold.

Ah, I think I’d rather have a bit of the warm, please…

Now ‘the bad news’ is that this cycle runs all on it’s own. Even the CO2. Not a thing we can do about it as near as I can tell. The good news is that it takes a few thousand years before anything really bad happens.

If by some fantastic means we find that liberating CO2 DOES warm the globe, it will be the greatest blessing we could bestow upon the planet to preserve it in the present state. Canada and Europe under a mile of ice will not have much “biodiversity”.

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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24 Responses to Pliocene Warm Period 3 C Warmer Than Today

  1. Baa Humbug says:

    Hi Chief

    This fine post reminds me I read somewhere about earths orbit intersecting clouds of dust and debris every so often, at which time we sight more meteors etc (I think)
    Maybe we intersect these clouds of dust every 100,000 years?
    The plunge into cold is so striking, with slow gradual return to warmth.

    It would be informative if it was possible for somebody(s) with better clear thinking skills than I, try and reconcile the various Milankovitch cycles

  2. David says:

    “If by some fantastic means we find that liberating CO2 DOES warm the globe, it will be the greatest blessing we could bestow upon the planet to preserve it in the present state. Canada and Europe under a mile of ice will not have much “biodiversity”.

    The seradependious accident of industrial CO2, minus the particulates of course, enforces a symbiotic relationship between warmth and life. I just went to my son’s school exhibition where they presented papers on energy trends in the US. Not one student understood this relationship, or understood that part of the reason consumption out ran domestic production was political choices. When I told these 9th grade students that, due to the increase in CO2, crops worldwide grew 10% to 18% more efficiently given the same amount of land and water, they looked at me with astonishment. Education now days is almost purely political, even, or especially in the “sciences”.

    Have you had a chance to analyze the pew poll that shows only 3% of republicans are scientist. I would love to know who provided what list of scientist from what disciplines, what age they were, etc, but cannot find the details. I suppose scientist must go through the same indoctrination my children are going through. Alas.

  3. pyromancer76 says:

    Jury duty completed, so time to turn my attention to your wonderful sleuthing into warm and cold and colder. I am not sure that I want to go the route of thinking (only): “Not a thing we can do about it as near as I can tell.”

    Milankovitch orbiting, galactic orbiting, and solar irradiance (variable) are givens for the most part, but ocean circulation as you mentioned seems key to the specifics. Major changes to ocean circulation seems to crewate the conditions for a dramatic climate regime change — even if it takes a few million years. (I often wonder if those Bond events might be due to some pattern of the ocean of which we are not aware.) The key to ocean circulation seems to me to be the position of our ever-moving (and growing) land masses. South America and Africa moved north during the Pliocene (I think they are continuing to do so, too.). Didn’t SoAm close with NoAm through the isthmus of Panama about 3.5 Mya? Major consequence! Pacific and Atlantic warmth separated; the Pacific contained a gigantic pool of warmth that was available for a long time. (Was this the source of the Pliocene maximum?) Meanwhile, cold Arctic and Antarctic waters were dropping temperatures in the now isolated Atlantic Ocean (so I read). Also the Thethys Ocean was closed by Africa moving north and Mediterranean formed — an almost enclosed bathtub — so currents in the middle could not connect.

    I am sure there are many other conditions that are important, but serious education must be expanded about how ridiculous the emphasis is on CO2, other than that we need more of it as you continue to show. We desperately need warmth and extensive flora and fauna if we are to thrive (not only to survive wretchedly). If we can more carefully and accurately research the conditions of warmth, we might be able to adapt both ourselves and Earth to keep and enhance more of it.

    Once I read Denny, How the Ocean Works, I marveled at H2O and its amazing conditions. However, the formation of cold in the depths of the oceans scares me — except that there are more nutrients in cold. I think good minds should be spending more time wondering what humans and smart technology can do.

  4. pyromancer76 says:

    P.S. Just received Mike Smith’s “Warnings: The true story of how science tamed the weather”. Good recommendation; hope it’s actually as good. Quite an “arrogant” title, but something like I am suggesting (to you, perhaps with the cast of characters you mentioned before) regarding gathering all our knowledge from every field (geology-plate tectonics, paleontology, oceanography, atmosphere-ology, etc.,with all the “global warming-CO2” nonsense extracted) and setting it to work intelligently on the “problem” of climate change. People are awake to the issue; it only needs to be redefined.

  5. Jeff Alberts says:

    How reliable are these ancient temp estimates? Seems the error bars would be about the same as the estimates, which makes them worthless.

  6. Jeff Alberts says:

    The seradependious accident of industrial CO2

    The what??

  7. David says:

    Jeff Alberts
    The seradependious accident of industrial CO2

    The what??

    Jeff, CO2 was produced in a sucessful endevour to generate enrgy for industry and citizens, the good fortune was that it also may prevent ice ages, and certainly grows forrests and food very efficiently.

  8. kuhnkat says:

    There is one alternative interpretation of the ice cores.

    The recent history is all that can be derived. The rest of the record is equivalent to looking at tea leaves to divine the past. The so called Science in interpreting ice cores is simply wishful thinking.

    I would point to the alternative estimates of ice aging and movement based on the aircraft found in the Greenland Glacier as a beginning to how wrong they are and how useless the analyses are at this point in time.

  9. E.M.Smith says:

    @jeff Alberts:

    I think he meant: serendipitous

    Either that or is making a pun on serendipitous AND how much of it we’ve let out of the ground.

    The possibility that it’s a word I don’t know is pretty slim as Google also doesn’t know it and found it in NO documents. Kind of amazing, really.


    You’ve got an absolutely new and unused word on your hands. Define it wisely and you could become a footnote to history ;-)

    Per the poll: Several problems.

    Who did they call? The Ph.D doing engine combustion research for Caterpillar? Or the ‘always answers the phone’ guys at the local school?

    For example, I never answer polls. None of their business. At real businesses, polls are often filtered out by the secretary for folks of importance. So between their polling method and the self selection bias, they will have bias.

    How many folks are “conservative not Republican”? If asked, I’d NOT say I was a Republican. I’m not. I’m an Independent Fiscal Conservative With Personal Liberties Please. Democrats are far more likely to toute who / what they are.

    The way it is stated is biased. 3% Of Republicans. Then it’s waved around as if to say that’s a terribly low percentage. Only 9% of Caifornia students qualify for the U.C. system. So if they were evenly split as Republicans, Democrats and Independents: You would get “Only 3% of Califonia Students who graduate UC are Democrats”…

    There is a hidden agenda in that statistic, and it stinks. The purpose is to paint Republicans as non-thinking. Not scientific. Nothing could be further from the truth. I’ve found far more of the ‘thinks clearly’ folks to be conservative and farm more ‘whacky fuzzy’ thinkers with the Democrats (and the worst are the Dimocrats).

    Finally: What did they include as a “Scientist”? The “Social Sciencies” that pumps out Political Indoctrination Degrees by the millions? Sorry, but I took Sociology at UC. This was 30+ years ago so it will be far worse now. At that time it was ENTIRELY “Loony Liberal Indoctrination Boot Camp”. Period. Every scrap of it was “get whitey” or “Men are EVIL” or “Western Civilization Raped The World”. I’ve a long story about that which I may tell some day, but the bottom line is that you only passed (and with a B+ IIRC) if you parroted the “spew”. Failure to do so got you a fail (even if they had to re-score tests to do so, and they did.)

    So, survey “Scientists” by polling the Social Scientists at universities and I’d suspect you can get a 100% number as non-Republican. Survey the Republicans at a Southern Baptist Church in, oh, backwoods Alabama and you will not find many Scientists (as they don’t work there).

    And even if you survey a representative sample, exactly what percentage of the whole population are scientists anyway? Of the 9% that enter UC, most go into non-science fields. Letters is larger than Sciences in the College of Letters and Sciences. (Though they’ve relabled some of the Letters as Sciences such as Sociology) And do you count the Engineering College as “Scientists”? Or do they “just make things” so it’s not “Science”?

    I saw a BIG sorting out at the front door. Folks who “think well and analytically” went to Engineering (with a few going into hard theoretical Sciences like Chemistry and Physics); while the Fuzzy Thinkers went into the “Social Sciences” and folks with creative skills went into the Arts.

    So if you exclude Engineers as “not Scientists”, and many folks do, as Engineers usually do design, not research; then you have a very small part of the population that are “Scientists” and they will be dominated by the “Social Sciences”. (Of the dozen or sections of Chemistry 1A with 400 head per class, only about 200 made it to Chem 1D. It was the FIRST of the “separator” classes. I went on to take Organic and upper division genetics 100 A+B. By that time the cohort was down to about 50 folks. Of them, one in 2000 would make it to Med School. That was when I ‘did the math’ and changed majors… Over in Social Sciences land, the Sociology 1A class had about the same number of sections and size as Chem 1A. But the size did not dimmish with progress ‘through the ranks’…)

    So those are the places I’d start looking for stupidity in the poll…

    @ Jeff Alberts (again):

    I trust them much more than the modern record. They are based on things like isotope ratios and formanifera types and sediment deposition lines. Things it’s very hard to manipulate. So, for example, the amount and kind of shell deposited in the mud tells you alot about the kind of life that lived there; and that tells you what the temperture was as life is fairly conservative about it’s biochemistry.

    In particular, there are some inter-species competitions where just a degree or so causes a shift. Like Polar Bears and Brown Bears. They are ALMOST the same species and can, in fact, cross. Yet there is a line where the two species meet. And that line moves with the ice, that moves with the temperature. You just don’t find Polar Bears down in Vancouver (other than in the zoo ;-)

    A simillar thing happens with foramanifera et. al. but you get to add two more subtilties. The relative deposition rates of different isotopes (Oxygen IIRC) is a fairly fine grained temperature indicator for the ocean at large and the rate of growth of cold blooded things tends to be temperature dependent so in some cases the rate of growth tells you about temperatures (back to that relative growth of two species thing, as some grow faster than others)

    Now I could see them screwing up the NUMBER they assign to it (does this or that level of O18 mean 8 C or 9 C ) basically, having the calibration off. But the relative temps are pretty darned clear. (And I think the ‘calibration’ has been done fairly carfully too with modern test areas.)


    Per the book (I’ll get to the longer comment after a coffee refill ;-) – Let me know how you like it. I’m thinking of buying a copy. It would save me all the work of writing my own book on climate AND I’d still get to have a book on the shelf with “my name” as author 8-)

    Yes, I’m a “Mike Smith” too. There are at least 3 of us currently active on the skeptic side. But don’t be too impressed. Everywhere I’ve worked there has been constant statistic of “One Mike Smith per 2000 working population” (within the granularity of the population) so there are a LOT of us. Major part of why I use “E.M.” as that seems to be modestly unique an identifier.

    The major problem with “doing anything” to stop it is that it looks like orbital mechanics and continent positions dominate. Can’t change either one. So we’re down to a limited set of options… More on that after a coffee refill…

  10. E.M.Smith says:

    @Baa Humbug:

    If you would like to understand the Ice Ages, the best read I can recommend is:

    Ice Ages, Solving The Mystery by Imbrie (Katherine and John)

    It covers the history of the solution, with quite a cast of “characters”. Along the way you learn the mechanics of it with little discomfort at all ;-)

    It is just a great little book that’s a fun read and you learn some things too. It’s chock full of little nuggets, like the fact that Milankovitch did all his calculations by hand with a fountain pen while in prison (during one of the wars he was captured as a solder of sorts… so took the several years opportunity to work on his passion, that he’d not really wanted to set asside for the stupid war in the first place… talk about silk purses and pigs ears…) Every day he would rise, and start calculating in his notebook. 8 hours a day for years…

    Basically, there is ONE configuration of the orbit that lets the ice melt (now) and we have an ‘interglacial”. That’s pretty much it. The ‘big deal’ is summer heating. You need enough to melt the Arctic Ice Cap in the summer, or you stay frozen. (Nothing melts at either pole in winter, and the S.Pole is always frozen and never melts due to the body of land there). We’re ‘right on the edge’ of never leaving an Ice Age Glacial, but can, sometimes, just barely get the N.Pole melted and enjoy times like now. Then the orbit shifts a bit more in it’s regular cycle of precession and change of circularity and the Arctic Winter Snow doesn’t melt one summer, but stays…. and we head into the next glacial as the albedo feedback kicks in.

    That the Lefty Loonies WANT the Arctic Ice to stay through the summer bothers me more than you can possibly imagine. They are positively CHEERING for the destruction of everything down to Chicago, Paris, Bejing. Just insanity. And they have no clue how it works.

    The major mystery is why the shift from a 41 kyr period to a 100 kyr cycle (on the graph above). But when I look at the detailed graph, the last two look more like 120 Kyr and it looks to me like there are 2 minor ‘blips’ in the middle. Like we’ve got 3 “attempts” at a 41 Kyr cycle, but only one in three, the strongest, made it ‘over the hump’. It’s now harder to get out of the ice age well. We’ve sunk a bit further.

    So my ‘take” on it is that the (known) 41 Kyr orbital cycle used to be ‘enough’ and now it’s not, except for the one in 3 events when it lands just right on top of some of the other changes (like the excentricity of the orbit changing). So look back at the 5 Myr graph. Our ‘depth of cold’ is far more now, so the ice is thicker at the bottom. It will take more heat longer to ‘dig out of the hole’ and the ‘minor nodes’ no longer can do that much digging.


    Well, there’s always hope.

    We can hope that CO2 is a magic gas and that we can burn enough fossile fuels to keep things as they are now even as the orbit changes send us into cold land.

    We can hope that techniques like putting soot on the ice could “manage” the glacial growth.

    We can hope that we could make enough of the “super greenhouse gasses” to keep things warm.

    We can hope that the closure of the gap between North and South America WAS critical and, faced with the prospects of losing everything north of Chicago the world would agree to nuclear excavation of Panama

    has a nice description of it. (So, Pyromancer76, you will likely find it an interesting page to visit)

    But as I’m fond of saying

    “Hope is not a strategy. -E.M.Smith”

    FWIW, there is some confustion over the term “Ice Age”. It is used to mean two different things. One is properly called an “Ice Epoch”. They are periods that come around every few hundred million years. The other is properly called a “Glacial” or “Glaciation”. So I’ll often talk about an “Ice Age Glacial” as opposed to an “Interglacial” like now when the ice is gone, but we’re still in an “Ice Epoch” as the ice is coming back. The term “Ice Age” can mean either that returning “Ice Age Glacial” or the overall Ice Epoch we are in. Carefully keeping those two ideas straight helps a lot of things be more clear.

    The “Ice Age Glacial” cycle is driven by the orbital mechanics. (See the book ref. above).

    the “Ice Epoch Cycle” looks to be driven by our position in the Glactic Arms. A very readable description here:

    If you look in his fig.4 at 600 MYBP

    you find the last time we went through this arm of the Galaxy we had a lot more Ice Epoch, so it looks like we have lots more Ice Epoch to come. Further, if you look at the little “snow mountain” humps in the 3drd down panel labled “Epochs with Glaciation” and note our hump vs the hump then… it looks like we’re still climbing our hump…

    So if you wanted to have an even longer term perspective than that 5 Myr chart up top, this Fig 4 gives you a 1 Billion Year perspective.

    And the bad news is that it makes it look like we’ve got a while longer to have worse and deeper Ice Ages in this Ice Epoch. The good news is that we’re past the spiral arm, things DO get better from here (eventually) and these things have some stochastic component to them so if we’re lucky we can hope that we don’t get a long double dip like 600 MYBP but more a shallow single like 750 MYBP or even a ‘little dipper” like 150 MYBP.

    And, I suppose, the “best news” is that since we only evolved in the last couple of million years and we are still evolving (all things are) we’ll be a completely different species inside a couple of more million years anyway so any time scale longer than the right half of that 5 Myr graph is not very useful for “us”.

    At most, we have to deal with the first 100 years or so of an 80,000 year growth of ice, then it’s the ‘kids’ problem (and, don’t forget, we gain more tropical land as the sea level drops! Plenty of time to relocate.) Then after 100,000 years living in the topics, we get another interglacial. Couple of more cycles like that and we’re probably a different species by then. As they say “Not My Problem” by then ;-)

    So, bottom line: I’ve calculated that the Ice Sheet (as opposed to the snow) advances about 800 FEET a year. The ice builds almost linearly (with jaggies) over the 80,000 years. You can WALK fast than that in one day a year. It’s just not worth worry. In one lifetime, you must worry about, roughly, an 8000 foot advance. Mile and a half. 2 Km. If you live, presently, 2 Miles from the foot of a glacier, you need to move before you grow old and die.

    I can live with that. For the more skittish, I suggest a move to somewhere close to the Equator.

    In places like the Andes (say, from Columbia through Ecuador and Peru to, perhaps, even northern Chile) the ice moves down the mountains. But not very much. The glaciers that are still there will regain their former reach, but that’s a very short reach (look at the moutain valleys. Those that are U shaped are glacial. Those that are V shaped are not. Don’t live in a U shaped valley ;-)

    So you can “choose your climate” by moving a few thousand feet up and down the mountains. At 3000 meters it’s cold and snowy. At 2000 meters it’s presently about a perfect spring weather. At 0 MSL it’s hot and tropical. You’ve got 2000 m of elevation to move At Most. So I’d guess that 1000 m is going to stay “just fine”. That gives 1000 m to move (from 2000) over 100,000 years of cycle. I make that 1/100 m of elevation change per year. So if you are an adult, with 40 years life left, at most you have to deal with 40/100 or 40 cm of elevation change. So put your bed on the floor ;-)

    Yeah, that’s about 1 1/2 feet of elevation change. Be still my heart… (Did I mention that geologic time scales are long and slow ;-)

    The only thing that really needs “mitigation” is that we have major snow events faster and sooner (and major rain / flood events) so crop failures happen faster and sooner. Primarily at high latitudes (Canada, Russia, Argentina) Until the ice builds up, you don’t have the added tropical land exposed. So there is a ‘transition period’ early on where food is a bit harder to come by and land not yet increasing. So “God Bless CO2” as it’s making crops grow faster at a rate far in excess of any snow advance. Lets just hope it stays that way…

    And I hope that answers your concerns…

  11. Thanks for an interesting and thought-provoking post.

    If you haven’t, you should read William F. Ruddiman’s “Plows, plagues, and petroleum: how humans took control of climate” (2005). Ruddiman’s thesis is that anthropogenic global warming appears to have started just about the time agriculture was invented. The effects so far have been almost wholly beneficial — Ruddiman thinks that AGW is indeed
    preventing the onset of another glaciation, and makes quite a nice (if very speculative) case for it. A very cool book, highly recommended.

    The Wikipedia summary at,_Plagues_and_Petroleum is reasonably accurate.

    I should visit here more often.

    Best regards,
    Peter D. Tillman
    Consulting Geologist, Arizona and New Mexico (USA)

  12. Baa Humbug says:

    Thanx E.M. Yes that answers my query (not concerned at all)

    I had most of Nir Shavivs articles on the old puter, time to download them again, this time to USB key as well. I like reading his stuff.

    I’ll first search for that Imbrie book locally.

    E.M. Can I say what a pleasure it is to have someone take the time and effort to answer queries with such detail as you do. You’re a rare shining light in the blogsphere and I thank you very very much for that.

    here, have a cyber hug from me ()

  13. Peter Offenhartz says:

    I have a question about the EPICA and Vostok temperature records: Are they both records from arctic or near-arctic regions? (The caption says antarctic. Is that correct?) The reason I ask is that one thing we know about the current warming is that it is strongest in the arctic. The reasons for this are pretty well understood: The change in albedo when ice turn to liquid provides a positive feedback that enhances the warming trend.

    If the EPICA and Vostok records are arctic records then the magnitude of the temperature changes that they indicate may well be highly exaggerated with respect to temperature changes in the rest of the world. This could be true even if the records are antarctic if there had been water formation during the warmest periods.

  14. Jeff Alberts says:

    Jeff, CO2 was produced in a sucessful endevour to generate enrgy for industry and citizens, the good fortune was that it also may prevent ice ages, and certainly grows forrests and food very efficiently.

    I got that, I was just poking fun at your extreme mangling of the word I bolded in your quote. ;)

  15. E.M.Smith says:

    @Baa Humbug:

    I’m happy to share what I know… and I’m very happy to have someone appreciate the detail. I’ve often been “whacked” for being too prolix by folks who only want the 10 second sound bite. But I’m much more driven to give a complete and correct answer than to give a sound bite that misses the mark (as they all must do).

    @Peter D. Tillman:

    I’ll have a look for it. To the extent he’s right, it would be the best possible news we could have.


    Yeah, those aircraft were WAYYY down in the ice after only, what, 50 years?

    places it at a couple of hundred feet down and a mile of drift.

    Made me wonder about the ‘ice record’.

    But there are some mitigating things. Presure melting, for one. The metal can drift through the ice where ice layers themselves would not move. And local parts of the ice can move much faster than the more stable bits.

    So at some point you must accept something as ‘true enough to use’ or you will know nothing. (And while that might be the more accurate statement of our actual knowledge, it’s not very useful ;-) Until there is some strong evidence that the “ice core guys” have screwed the pooch too, I’m willing to give them the benefit of the doubt.

    But, no, I’d not call it “settled”…

    OK, back at that 5 My chart. Notice it says “from sediment” not “from ice cores”. That means we have a ‘cross check’ on the ice interpretation to some extent. There are also ice rafted debris lines and other cross checks. Given all that, I think the history of the Ice Age Glacials is pretty accurate. (Little things, like the limestone formation in Florida right in the times and places you would expect from when the last Interglacial happened, and the drowned dead Reef Systems at low water marks in the times and places you would expect from the high ice times.) So with that much ‘cross check’; I’m willing to accept the basic veracity.

    @Peter Offenhartz:

    Per the wiki:


    Vostok team.
    Main article: Vostok, Antarctica

    As of 2003, the longest core drilled was at Vostok station. It reached back 420,000 years and revealed 4 past glacial cycles. Drilling stopped just above Lake Vostok. The Vostok core was not drilled at a summit, hence ice from deeper down has flowed from upslope; this slightly complicates dating and interpretation. Vostok core data are available.[29]

    EPICA/Dome C

    The EPICA and Vostok cores compared
    Main article: European Project for Ice Coring in Antarctica

    The EPICA core in Antarctica was drilled at 75°S 123°E (560 km from Vostok) at an altitude of 3,233 m, near Dome C. The ice thickness is 3,309 +/-22 m and the core was drilled to 3,190 m. It is the longest ice core on record, where ice has been sampled to an age of 800 kyr BP (Before Present).[13] Present-day annual average air temperature is -54.5 °C and snow accumulation 25 mm/y. Information about the core was first published in Nature on June 10, 2004. The core revealed 8 previous glacial cycles.

    Although the major events recorded in the Vostok, EPICA, NGRIP, and GRIP during the last glacial period are present in all four cores some variation with depth (both shallower and deeper) occur between the Antarctic and Greenland cores.

    So, yeah, they are both Antarctic cores in the graph, but agree with the Greenland cores (modulo some depth variations, as one would expect).

    I’m willing to accept that the folks who did this work most likely did it properly. If you can dig up some reason not to trust them, well, I’m willing to be skeptical. (Then again, folks already know that about me ;-)

    Given that our present status is about as warm as it gets (modulo a degree or two) and we’ve got incredible cold at the S. Pole, I’m pretty sure we didn’t have a whole lot of added ‘water’ issues there over the past ice age glacial cycles… Greenland, IIRC, has some ‘water issues’ around the edges and in some specific locations. Whole chunks of time are missing from the record. A core matches an old antactic (or central Greenland) core, then misses a bunch, then picks up again at a later point in the more intact record. Nope, don’t recall exactly where I picked up that bit. I think it was a Discovery or Nat.Geo. show on ice cores and Greenland / Antarctica.

    Oh, and again a reminder that much of the data (especially up north) is from sediments, not ice cores. The quoted article about warm thriving biotica for example uses sediment cores. (I’m pretty sure ice cores don’t go back anywhere near that far. Then again, we’ve not drilled everywhere so there might be a surprise awaiting discovery). FWIW, the “warmist” side of the debate can use this to it’s advantage. It DOES indicate that during very warm times sea level rises (covering southern Florida) and the Arctic warms (probably to the point of ice free). So while this shows that “nature did it” it also shows “we probably would not like it”. Which then punts the whole thing back to “what impact DOES CO2 have?” be it natural or man made.

  16. Peter Offenhartz says:

    Thank you for the link to the wiki/ice_core reference. I note that close examination of the temperature record shows that the rate of cooling does not seem to exceed 1 C per thousand years. Make of that what you will, but if we are waiting for global cooling to save us from global warming we may have to wait a long time.

  17. E.M.Smith says:

    I’m thinking it’s more like waiting for Global Warming to save us from Global Cooling (which is clearly the case in the historical records for the last 5 Myr (with ice age oscillations) and for the last 7000 years since the peak of this interglacial.

    Oh, and since 1998 for the present “trend”….

    BTW, the longer the time base you look at the more you have ‘over averaged’ and lose detail. We have dramatic small swings even inside that 1 C / long-time drift. So we can have VERY fast cooling over 100 years and it won’t even show up as a blip on the ice graph of 100,000 years. (Like the Little Ice Age and “1800 and Froze To Death” or the year without a summer when it snowed in New England in summer).

    Near as I can tell, the folks in Europe are still waiting (and the UK in particular) to be saved from the snows of the last couple of years.

    The PDO has flipped, the AO is in the cold phase. We’re back in 1950 or so and headed into a long cold run. That’s going to take the portion of “warming trend” that was actually misconstued 1/2 PDO cycle out of things. As that happens, we’ll get a handle on any real long term trend, and find out if we’ve stopped the plunge, or just slowed it down a tad.

    From what I’m seeing in the world today, we’ve got no trend at all. So far it’s almost an exact replay of the last time through this set of events.

    Flooding in Central / South America.
    FEET of lake effect snow downwind of the Great Lakes.
    Australia having heavy rains again (been a while).
    Europe with more snow than they’ve seen in decades, but about the amount from the past and in keeping with what I remember from when my Mom talked about it.
    “Loopy Jet Stream” as I remember from when I first saw it on our old B&W TV.

    Looks to me like “same old same old”.


    VERY high snow level in the California Sierra Nevada Mountains. About 1958? we drove up (in a ’56? Chevy) to see it. 18 feet over the roadway IIRC. It was like driving in a tunnel but without a top.

    Flooding as it melts (mitigated by the dams we’ve built since then, though). When I was about 6? 9? Call it about 1960? the Feather River flooded. We all went out to watch it. Took out a segment of the old bridge. Part of the justification for building the Oroville Dam.

    Long cold cloudy winters with the “Pinapple Express” delivering storm after storm.

    Crop failures in Russia, Canada, and Europe (due to cold, snow, and rain). Not catastrophic, but something we’ve not had for a while.

    The Great Salt Lake will start to rise again. In a couple of years, they will have to re-start the pumps that have been shutdown for about 30 years. (Hmmmm. 30 years. Where have I heard that number before ;-)

    I’ll stop there. Anyone who wants to know the weather future at this point can, IMHO, just sync the history of 1950 (ish) with 2010 and start reading.

    We’ll know pretty quick how close the match is.

  18. POUNCER says:

    I probably repeat myself, here …

    I see it like monetary policy; inflation vs deflation. We’re not sure what in the business cycle triggers extremes of either. We don’t have good remedies for either. But of the two, we have a little less misunderstanding and a little less chaos with inflation than with deflation.

    And of global climate change — warming versus cooling — due to CO2, we have a little more control and a litter better understanding of warming than we do of ice ages. If we have to risk one or the other, the “precautionary principle” leads me to favor more warming — more CO2 production, more industrial waste heat, more energy sources in general.

    Because it’s actually all too easy to shut down a plant. What’s hard is putting one up.

  19. Viv Evans says:

    Just a very small footnote to this remark by you, dear Chiefio:

    “In particular, there are some inter-species competitions where just a degree or so causes a shift. Like Polar Bears and Brown Bears. They are ALMOST the same species and can, in fact, cross. Yet there is a line where the two species meet.”

    It’s not a line so much as a zone, which in zoological circles is known as ‘hybrid zone’, because two very closely related species can live together and cross-breed.
    It has been studied in many species, the one I recall best looked at land snails.

    Thanks for this excellent article, and the comments.

  20. David says:


    You’ve got an absolutely new and unused word on your hands. Define it wisely and you could become a footnote to history ;-)”

    Ah well, at least you did credit me with one legitimate new word to you from a past post, remember noumena? At any rate, proper discernment of a comma can not account for a climate coma, which I hope to avoid through reading blogs such as yours.

    BTW, today I just drove 500 miles from Napa to San Diego, non stop rain the entire drive.

  21. E.M.Smith says:


    You might like the most recent posting. I’ve got a ‘weather radar’ image up of some of what you drove through.

    Yeah, end to end we’re getting walloped with rain…

    You have my condolences for driving in it. This morning the spouse and I took one look at what was coming down and the VERY gusty winds blowing limbs all over and decide to just skip church today… didn’t need to be THAT close to God all THAT quickly ;-)

  22. Dan Kurt says:

    re: All of the musings on this site and this article and the comments

    Remember the story of the Blind Men and the Elephant.

    There is more to the story than what your specialized fields have uncovered.

    Factor in POLE SHIFTS, that is, crustal movements on the mantle happening over hours probably.

    Also consider that Plate Tectonics as currently taught is most likely hogwash and that an EXPANDING EARTH hypothesis for at least the last 180 million years deserves investigation.

    Dan Kurt

  23. Brian H says:

    Can you give us some numbers (analysis) of the sequencing on the 450Ky chart of the CO2-temp sequences, lags, etc.?

  24. Level_Head says:

    Hello, Chiefio!

    A couple of things: There is an increasingly visible connection between the closing of Central America and the ice age cycle. The joining of N and S America by volcanic activity, which was happening over the past seventeen million years and completed about seven million years or so back, rerouted what we now call the Gulf Stream, which used to simply flow between Atlantic and Pacific. (The other end circled around S America.)

    That heat transport engine has been greatly changed — and the timing looks very suspicious indeed. It appears to have changed the “stable point” and caused a process of millions of years seeking a new one — which we now seem to have found, perhaps a million years ago or therabouts in the Pleistocene.

    Perhaps we can improve on this — the drop of sea level would be a much bigger problem than the rise.

    Here’s a paper saying that Central America’s closure “is all a coincidence” — but still interesting.

    Click to access MolnarPaleo’08.pdf

    The second issue is polar bears and Vancouver. They are indeed found there — as they have to move south during each glaciation. We have fossils of polar bears from London and Spain, because of course they cannot live at the north pole during an ice age.

    They migrate to get away from the cold. Even though they like it colder than we do, they cannot live without the food that blue water brings every year — and that food moves south, too:

    The oldest known polar bear fossils are a relatively large right ulna from presumably Early Weichselian (approximately 70 000 BP) gravels of the Thames at Kew Bridge, London, and a left lower jaw from .80 000 BP deposits on Svalbard (O. Ingolfsson, personal communication).2 The Kew Bridge find induced Kurten (1964) to create a new gigantic Late Pleistocene subspecies Ursus maritimus tyrannus. Stuart (1982) calculated that the Kew locality was at least 140 km from the Devensian (last glaciation) coastline, based on the assumption that sea level was at its lowest then. Further, the presence of a marine mammal fauna, including ringed and bearded seals, suggests that polar bears too were present in the southern North Sea during the Late Pleistocene (at several colder intervals during the Weichselian) (Post 2005). Also, it is possible that outlines of bears in the Paleolithic cave of Ekain, northern Spain, may indicate that polar bears drifted south from the edge of pack ice off southern England (see map on the cover of Preece [1995]) to the northern coast of Spain during heavy ice years toward the close of the Pleistocene. I interpret the bears to be twin subadult polar bears from their teardrop body shapes (Bahn and Vertut 1988: Fig. 90). These images were probably made during the Magdalenian (approximately 17 000–12 000 years ago).

    (From: C.R. Harington The Evolution of Arctic Marine Mammals,2008)

    Best wishes for an extraordinary new year!

    ===|==============/ Level Head

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