Guest post by David Archibald
Baby boomers like me have enjoyed the most benign period in human history. The superpower nuclear standoff gave us fifty years of relative peace, we had cheap energy from inherent over-supply of oil, grain supply increased faster than population growth and the climate warmed due to the highest solar activity for 8,000 years. All those trends are now reversing. But it will get much worse than that. The next glaciation will wipe out many countries and nothing will stop that from happening. For example, the UK will end up looking like Lapland. As an indication of just how vicious it is going to get, consider that there are rocks on the beaches of Scotland that got blown over on ice from Norway across a frozen North Sea. As scientists, our task is to predict the onset of the next glaciation.
Onset of interglacials is driven by insolation at 65°N. That is where the landmass is that is either snow-covered all year round or not. It seems that insolation above 510 watts/sq metre will end a glacial period. For an interglacial period to end, the oceans have to lose heat content so that snows will linger through the summer and increase the Earth’s albedo. Thanks to the disposition of the continents, our current ice age might last tens of millions of years yet. From the Milankovitch data, this graph shows insolation at 65°N from 50,000 BC to 50,000 AD:
The green box has the Holocene ending at 3,000 AD – an arbitary choice. Insolation is already low enough to trigger glacial onset. For the last 8,000 years, the Earth has been cooling at 0.25°C per thousand years, so the oceans are losing heat. We just have to get to that trigger point at which snows linger through the northern summer. Solar Cycle 25 might be enough to set it off. By the end of this decade, we will be paying more attention to the Rutgers Global Snow Lab data.
From the source at: http://most-likely.blogspot.com/2012/03/milankovitch-cycles-and-glaciations.html
Model input is obliquity and precession and model output is the inverted δ¹⁸O record, with zero mean during the Pleistocene, from Lisiecki and Raymo 2004 and Huybers 2007. Lisiecki and Raymo use orbital tuning to constrain the age of the benthic records, while Huybers explicitly avoids this, consequently the two datasets are occasionally completely out of phase, but generally in good agreement, especially in the late Pleistocene.
As fitness function we take the product of the sum of squared errors (SSE) between the model and the two reference records from 2580 thousand years before present, with 1000 year timesteps.
For the longer term perspective, this is a combined crop (to make a continuous timeline) of the two fulls panel from the model prediction of the Milankovitch data.
The time period represented is from approximately 450,000 BC to 330,000 AD. The scale on the vertical axis is change in O18 content. There is a very good hind-cast match between the model and past temperature change as shown by the work of Lisiecki et al 2005 and Huybers 2007. The next glaciation is fully developed between 55,000 and 60,000 AD, with the next interglacial 20,000 years after that.
References
Huybers, P., 2007, Glacial variability over the last 2Ma: an extended depth-derived age model, continuous obliquity pacing, and the Pleistocene progression, Quaternary Science Reviews 26, 37-55.
Lisiecki, L. E., and M. E. Raymo, 2005, A Pliocene-Pleistocene stack of 57 globally distributed benthic d18O records Paleoceanography, 20, PA1003, doi:10.1029/2004PA001071.
Source Data: Download the consolidated data, including orbital parameters, insolation calculations, reference data and model output: Milankovitch.xlsx
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
tallbloke says:
September 16, 2012 at 10:45 am
Thanks Nigel. Probably the most important comment on the thread.
Looks more like propaganda to me, but at least it is right that the next glaciation is tens of thousands of years away.
davidq says:
September 16, 2012 at 12:18 am
Perhaps we need to widen and deepen the Panama canal. Didn’t the current onset of glaciation start occurring after the Atlantic and Pacific was cut off?
20 Miles wide, 300 feet deep. doable?
=============================================================
Google “Ploughshares”.
There was once a plan to make a sealevel canal to replace the Panama Canal. The leading route was through northern Columbia. The only problem had to do with all the Nukes it would take ….
(It would be kinda’ fun to watch the the reaction of the Envirorn-mentalist to learn that the solution to Ma Gaia’s latest prank was to set off a string of Nukes … through a rainforest no less!)
CONSIDER THAT THERE ARE ROCKS ON THE BEACHES OF SCOTLAND THAT GOT BLOWN OVER THE ICE FROM NORWAY ACROSS A FROZEN NORTH SEA
True! Want proof? Never heard of the SLIDING ROCKS OF DEATH VALLEY did you!
“These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa cutting a furrow in the sediment as they move. Some of these rocks weight several hundred pounds.”
There! Put that in your pipe and smoke it! And don’t give me any claptrap about Death Valley not being a frozen North Sea. The principle has been established by scientific observation. Next thing you know you will be denying the greenhouse effect as it is so widely applied. Wait! Wait! This is about the coming iceage — forget I said anything about the greenhouse effect. Sometimes I just get so confused.
Eugene WR Gallun
LazyTeenager says:
September 16, 2012 at 11:39 am
There is a contradiction here.
One graph says the ice is back in 3000 years. The other graph says its back in 10-15 thousand years.
The latter was my understanding so personally I am not worrying about glaciers in the near term of the existence of western civilization.
==================================================================
Whichever, you’d need to add 100+ years to it. Hansen said we’d all be well on our way to dying off by then. “Nature can’t take it’s course” till we’re all gone. Isn’t that the mantra? Nature would be fine if it wasn’t for us?
Eugene WR Gallun says:
September 16, 2012 at 10:57 am
I don’t think the locks would stop the nukes from working.
It seems both Axelrod and Svalgaard don’t know what’s going to happen, it’s a guessing game and rightfully so. Our knowledge is completely insufficient to make determinations about the next ice age. Axelrod seems a bit too certain of his guess and that is most likely where he is wrong; Svalgaard is too certain it isn’t the sun and he doesn’t *know* either. We are in an interglacial and the next one is coming but who knows when. The only thing I do know is not to let any of the morons with ideas of mitigating an ice age get any where near the switches to attempt any of the Rube Goldberg type idiotic ideas posted here.
dallas says:
September 16, 2012 at 11:51 am
Leif said, “no, you are wrong” I don’t think so or I wouldn’t have said it
You obviously didn’t bother to read: http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf
“The available evidence supports the essence of the original idea of Koeppen, Wegner, and Milankovitch as expressed in their classic papers [Milankovitch, 1941; Koeppen and Wegener, 1924], and its consequence: (1) the strong expectation on physical grounds that summertime insolation is the key player in the mass balance of great Northern Hemisphere continental ice sheets of the ice ages; and (2) the rate of change of global ice volume is in antiphase with variations in summertime insolation in the northern high latitudes that, in turn, are due to the changing orbit of the Earth.”
David Ross says he doesn’t get the mode of traction. That’s easy, 650 million years ago we were on the edge of being a snowball with ice at the equator. Later on, glacial ice melted at the bottom and left the debris of thousands of tons of rocks as it traveled and that’s what we can see in the US West, that proves the ice age happened.
Not sure if a link to this paper has been posted above?
AN URGENT SIGNAL FOR THE COMING ICE AGE
By Peter Harris
http://icecap.us/images/uploads/ANURGENTSIGNALFORTHECOMINGICEAGE.pdf
Comments regarding this old paper?
David Ross:
i believe that there is a better sealevel route from atlantic to pacific through nicaruaga. it got a bit of interest when the smart guys started talking about nuculear [sp] excavation in the fifties.
however hidden rice bowls got into the act (mostly panamanian and the threat of the loss of traffic revenues).
then someone pointed out the facts of radioactive fall out (they were not as knee jerk scared of it then) and another group figured out which way the subjective and political winds were blowing.
now days the job would only rate a couple of column inches in the federal rfp advertisements.
catapillar, letourneau and several others would smile though.
C
I see that it has already been posted above, so sorry!
Dennis Nikols, P. Geo. says:
September 16, 2012 at 8:57 am
“Very interesting and much food for long term thought. That said, I am taken back in time back to the 1970′s when all the models showed cold was bold. Then again to a later time when models showed heat was neat and CO2 was the key. We must all remember two things. This kind of long term anything based on proxies and models is great cosmology or mythology. Remember to keep a skeptical eye and Mother Nature plays with loaded dice.”
Its interesting how it was thought that cold would lead to calamity, droughts and famines would ensue. When it is relatively warm, then warmth leads to calamity, famines and droughts.
It says (to me) that the human race is never in a good position and good old big government is there to tell us how rotten we are, so that we pay surcharges and taxes to make it right – or until we go into a relative cooling period when the paradigm changes back again as to how awful we are for a cooling climate, and ought to be taxed for that.
Afterall, if you want big taxes from a product, the product has to be vilified first.
Well, it’s been nice knowin’ y’all. We’ve had a good Holocene together haven’t we?
In preparation for the glacial advance coming down from Illinois, I’ve gone over to Lowe’s and bought a couple hundred square feet of R-30 for the attic above the computer lab. I plan to wait it out, warm in the glow of my overclocked ‘386. At least until EPA shuts down the local power plant.
Mike in Houston
DavidG says:
September 16, 2012 at 12:33 pm
It seems both Axelrod [sic] and Svalgaard don’t know what’s going to happen, it’s a guessing game and rightfully so. Our knowledge is completely insufficient to make determinations about the next ice age.
You obviously didn’t bother to read: http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf
“The available evidence supports the essence of the original idea of Koeppen, Wegner, and Milankovitch as expressed in their classic papers [Milankovitch, 1941; Koeppen and Wegener, 1924], and its consequence: (1) the strong expectation on physical grounds that summertime insolation is the key player in the mass balance of great Northern Hemisphere continental ice sheets of the ice ages; and (2) the rate of change of global ice volume is in antiphase with variations in summertime insolation in the northern high latitudes that, in turn, are due to the changing orbit of the Earth.”
Leif Svalgaard says:
September 16, 2012 at 11:56 am
tallbloke says:
September 16, 2012 at 10:45 am
Thanks Nigel. Probably the most important comment on the thread.
Looks more like propaganda to me,
Says more about you and your allegiances than it does about Nigel Calder.
but at least it is right that the next glaciation is tens of thousands of years away.
Maybe, but we still don’t know for sure. Major league Icelandic volcanos could change things real quick.
Kev-in-UK
We agree completely! And the idea the mankind can “control” or manipulate Earth’s climate in any measurable way is the height of arrogance, ignorance or both!
Bill
There is more to it than this thread provides. See: “Ice Ages and Interglacials” 2nd ed. (403 pages) by D. Rapp (http://www.praxis-publishing.co.uk/9783642300288.htm)
JA says:
September 16, 2012 at 9:41 am
Until scientists can explain with a hi degree of confidence what caused all the historic periods of cooling, warming, ice ages, etc., – and so far they cannot – then all is conjecture. More importantly, scientists have yet to explain how it is that the earth can move from a ball of ice to a very warm period, or vice-versa.
ETC.
= = = = =
Pretty good.
Climate changes.
We know that.
We don’t know why.
WUWT produced, with its readers, a list of possible affectors of climate, some months ago. It was scores of variables long . . . .
Probably some of the notions/ideas/hypotheses above are right.
Which ones?
I don’t know, and I don’t think anyone else does.
From 10,000 [my guess] folk involved predicting climate, it is likely that a handful will get the next 20 years, and the next 500 years, about right.
And how many by luck?
Oh well, Monday dawns soon enouhg here – and I have a commute to the City.
have a great week – come warm or come cold.
Interested parties might wish to consult the figures from Elderfield et al Evolution of Ocean Temperature and Ice Volume through the Mid Pleistocene Transition http://www.sciencemag.org/content/337/6095/704.figures-only
The relationships between the orbital eccenticity and obliquity cycles and global sea levels and ice volume are show very clearly in their fig 4A and B. The 100,000 year eccentricity cycle is modulated by the 41000 year obliquity cycle.When earths eccenticity insolation drops below about 360 w/meter the eccentricity frequency dominates – earlier the obliquity frequencies dominate ( Figs 1a and 1c) and the temperature and sea level variations are smaller.
These major cycle are then themselves modulated by millenium frequency solar activity cycles and they in turn by solar centennial and decadal cycles and lunar orbital cycles, The realtionships between these orbital and solar activity controls on ocean and atmospheric temperatures and CO2 etc have recently been elucidated by Humlum et al http://www.sciencedirect.com/science/article/pii/S0921818112001658
Now that we know how it all works we can obviously forcaste possible climate and temperature trends for the next few decades with some chance of being more right than wrong. SST data show that there has been no net warming since 1997 with CO2 up 8.5%. The PDO suggests a possible 20 – thirty year cooling trend and the Livingston and Penn data suggest the possibilty of a coming Maunder minimum – little Ice Age. In short -in order to mitigate the effects of cooling on world food production we would do well to emit as much CO2 as possible until mid century at least.
If the first graph is any good (??) then
http://www.vukcevic.talktalk.net/toGl.gif
plenty of time to implement SNG Project
In an addition to my previous post I would suggest that Archibald might take a [look] at the SH insolation at 70 – 75 degrees because this seems to be the controller of Antarctic ice extent which is the main climate driver ( impacts excluded ) probably since Oligocene time.
standbythree says:
September 16, 2012 at 5:50 am
I stand corrected, with thanks.
uto says:
September 16, 2012 at 2:17 pm
agreed.- when it comes to genuinely NATURAL events – we can explain or understand very little. A good example would be genetic mutations – which are seemingly random events in ‘nature’ – sure, we could encourage some by radiation, etc – but the effects are generally quite random. If we consider something we supposedly know something about – e.g. volcanoes, and actually think about how predictable they are (not!), where are we on the risk analysis and risk management scale? I would suggest the only thing we can currently say, with all our study of volcanoes, is – don’t live near one!! Earthquakes would be another good example – sure, we can see/measure them, and we can see patterns – and we know they occur in certain areas – but ‘prediction’ – don’t make me laugh! – and this is a relatively well studied area of a relatively SMALL part of planet! I’d reckon ‘climate’ is at least a couple of orders more complex and massive than an earthquake or volcanoes (in terms of ‘size’) and yet the climate boys reckon they can predict it!! Yeah, right!
As you say – back to work tomorrow………
DavidG wrote:
Sorry DavidG for being too oblique, I should have been more clear.
I’m not an expert -just high school geography. But I live in Scotland and can recognize raised beaches and such. David Archibald makes it sound like the rocks are blown by the wind over the surface of the ice rather than carried with (within, on or under) the ice and deposited as erratics or morraines at its edge or when it retreats (which is the process you describe). My language was just an attempt at humour.
pk wrote:
I suspect a lot of it was political maneuvering i.e. to send a message to the Panamanians wanting more control over or revenue from the existing canal ‘Don’t get Bolshie or we’ll go build a better canal elsewhere.’
Eugene WR Gallun wrote:
Chill out Eugene.
Nobody is really serious -just throwing out science ideas for discussion. It wouldn’t happen in our life times. We’re talking about reversing an event that happened a long time ago.
Or here
http://www.whoi.edu/oceanus/viewArticle.do?id=2508
Ferdinand de Lesseps was not any fool. Neither was John Findlay Wallace. The French intended to build a sea level canal across Panama as did the Americans when they initially took over the project. Technology has moved on a bit since then.
In any particular group with similar interests some things are taken as ‘understood’. It is understood by (almost) everyone here that we’re talking about a sea level breach in the Panamanian Isthmus -wide and deep enough for, not just ships, but ocean currents to pass through. It would be a huge geo-engineering project but do-able (removing existing locks would be the least of problems).
Backing up your arguments with evidence and propounding them in a civil manner is the best way to convince people, but any fool knows that.
george e. smith says:
September 16, 2012 at 11:06 am
The author of the Milankovitch file (the link to it is provided above) is anonymous. It looks like he constructed the file to satisfy his own natural curiosity in February this year and then gave it to all Mankind in March. You are able to examine the file yourself and come to your conclusions on its veracity. As Lubos Motl said, I think it is really great.