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
Dr. Norman Page says:
September 16, 2012 at 2:37 pm
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,………. Now that we know how it all works…….
We are making progress. There is also Geo-Solar cycle (details in print soon) which attempts to explain the decadal temperature changes
http://www.vukcevic.talktalk.net/GSC1.htm
Dr. Page, the progress is slow but inevitable.
In the interests of balance anyone objecting to this climate model for being a model is obliged to do the same for all the warmist models.
http://en.wikipedia.org/wiki/Toba_catastrophe_theory
Links to human population bottleneck within the article
The sun gets its power from the outside – not inside!
http://youtu.be/A6p7PfCziiA
This might be a bit off topic, but does anybody know why the sea level graphs on the ENSO page have not been updated in a coon’s age?
tallbloke says:
September 16, 2012 at 1:23 pm
“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.
Or an asteroid could hit us, or Yellowstone could blow up, or …
None of this has happened the past 750,000 years while the climate has faithfully been following the Milankovitch cycles, so it seems a bit silly to invoke the ‘maybe this, maybe that’ defense.
Leif, Have mercy! That is one big a$$ spreadsheet and unfortunately incomparable with my dinky openoffice.
http://i122.photobucket.com/albums/o252/captdallas2/climate%20stuff/westerncaribbean.png
That is only 465,000 years of western Caribbean sea surface temperatures. Nothing personal, but I don’t live in the Antarctic. While I couldn’t load the solar forcing to do a proper comparison, I did eyeball a few similarities and a few not all that great matches with 8K and 10K lagged ice mass. I have no doubt that the orbital cycles are the cat’s a$$, I just don’t think ice is all that great an indication of what really happens in an ice age. Relating forcing to the main thermal mass of the Earth is a better route IMHO.
O/T but would this AP article see the light-of-day in 2012?
“Perhaps, after 10,000 years of retreat from the ice-age maximum, researchers turned on their instruments just in time to catch the stabilization or re-advance of the ice sheet,” Richard B. Alley of Pennsylvania State University, wrote in a commentary accompanying the Science paper.
http://www.usatoday.com/news/science/cold-science/2002-01-18-wais-thicker.htm
dallas says:
September 16, 2012 at 4:40 pm
Leif, Have mercy! That is one big a$$ spreadsheet and unfortunately incomparable with my dinky openoffice.
You didn’t get it from me [I think, but correct me if I’m wrong – which is it?]
Here is Alert Canada’s maximum temperatures over the past 6 months (it was about 1.5C above normal this summer but one can get the picture). Alert is basically ground Zero for the resumption of the ice ages (perhaps the Arctic sea ice not melting out at all in the summer would be another).
Alert July high temperatures of 20C (average 10C).
The snow melted out on June 16th and returned on Sept 5th. So there needs to be quite a bit of cooling here before the snow makes it through the summer and the July high temperatures.
Higher elevations and the Torngut mountain chain which goes down through Baffin Island into northern Quebec is another story but solar insolation needs to fall down to 440 W/m2 (versus today’s 480 W/m2) before the snow makes it through the summer. That may not happen for even 170,000 years.
http://s9.postimage.org/w8hkx23r3/Alert_Max_Temps_2012.png
Here is a Zoom-in of 65N June solar insolation for the next 5,000 years. It declines by a tiny amount over the next 1,000 years before going back up (for anywhere between 50,000 years and 170,000 years.)
http://s14.postimage.org/stpo0vf5d/65_N_June_Solar_insolation_10k.jpg
Glaciers will cover our crop land someday; but since Maize offers 3,700 kcal/Kg -1 while average beetle grubs provide 5,964 kcal/Kg -1 humans can survive as they “bug-out”. Sure it might be too cold outside to fish; but mealy worms are 20% protein which can thrive in a box.
A few points on the Panama Canal.
The Pacific Ocean is higher than the Atlantic/Caribbean, less than a foot, not enough to generate any power, but enough to establish a salt water flow from the Pacific and introduce a lot of Pacific species to the Caribbean. Don’t know exactly how that would work out, but probably not well.
Gatun Lake in Panama drains both directions to the oceans, This fresh water barrier halts a lot of species introduction.
We’d still need locks in a sea level canal, due not so much to the elevation difference, but due to the tides. Pacific tides are vastly greater than what the Caribbean can muster.
The best non-Panama route for a canal is through Nicaragua, following the river that forms the border with Costa Rica, then across Lake Nicaragua, then down to the Pacific. This still needs locks, because Lake Nicaragua is around a hundred feet above sea level, and the 10 mile stretch to the Pacific drops a steep 10 ft per mile.
If it warms up enough, maybe we’ll be able to keep the Northwest Passage open so we won’t need the canal so much.
Alert
http://www.wolframalpha.com/share/clip?f=d41d8cd98f00b204e9800998ecf8427ep052dtv9o8&mail=1
Kukla said: “The last glacial was accompanied by the increase of areally averaged global mean surface temperature, alias global warming. … But also increasing was the temperature difference between the oceans and the poles, the basic condition of polar ice growth. Believe it or not, the last glacial started with “global warming”!
Indeed known and the mechanism is well explained by Marcel Leroux -Dynamic Analysis of Weather and Climate, Praxis-Springer 2010-, whose work was respected by Kukla.
Leif, I clicked on the link in the post but for some reason the only parts I could read were links to your site.
http://i122.photobucket.com/albums/o252/captdallas2/climate%20stuff/westerncaribbeanwithTanganyika.png
While I am here, working back from the southern hemisphere I am finding internal oscillations that appear to respond at different rates to solar forcing depending on their thermal inertia. A.M. Selvam is one of those chaos kinda ladies which started me down this self organizing criticality road. With solar nudging instead of completely driving, the differences in the ice ages make sense, if you follow the energy through the system. 45S to 65S has the most stability, so it is the easiest starting point to explain were Milankivic appears to be off, when actually he pretty much nailed it.
@kadaka (KD Knoebel)
“Cover the moon in foil.” I’m not sure this would raise the brightness of the moon as seen from Earth. The current situation is that light away, from the center of the disk, as seen from Earth, can be reflected towards Earth by objects that cause the moon’s surface to depart from a perfect spherical geometry–from mountains down to the level of microscopic dust particles. Cover it with foil, and much of the light reflected to our line of sight from the vast majority of the surface, off the axis along our line of sight, will be reflected out into space.
I hope everyone understands there is no gainsaying TOA insolation history and future as described by Milankovitch cycles–this is basic physics working with zero unknowns. And what took Milankovitch a lifetime to estimate can be done with digital precision in seconds. Nor is there any gainsaying the delayed correlation between 18O and insolation. You may argue its interpretation but for my money typical reconstructions of T, ice mass, and ice surface explain the data adequately. And nobody is claiming M cycles caused the LIA or MWP; you add solar irradiance to orbital parameters to approach the whole picture.
The fact that M cycles are the obvious primary cause of ice ages is what conclusively took CO2 out of the picture even before its lag was determined, and it is dismaying to see skeptics deny their role in long term climate behavior. –AGF
We need a real good top shelf glaciation to save the reefs. No BS. The reefs are on their last legs according to large amounts of public funding.
http://www.smh.com.au/environment/climate-change/time-running-out-to-save-coral-reefs-scientists-say-20120917-260yg.html
Thank goodness the SMH is always on the ball with quality scientific articles like this one.
regards
http://www.brisbanetimes.com.au/environment/climate-change/staggering-arctic-ice-loss-smashes-melt-records-20120917-260zu.html
anyone lese spot the hubris.
The Arctic icecap alone regulates the earths temperature. I thought it was Big Als contrails.
regards
Leif Svalgaard writes,
“This is not Archibald’s assertion, but that of Milankovitch, Koeppen, and Wegner back in the 1940s. And most of Archibald’s article is borderline wrong. E.g. if you look at his first Figure it should be evident that temperatures the next 30,000 years are heading up, not down.”
If you look at that first chart again you can see that it is ALWAYS below the 510 watts/sq metre threshold therefore no true warming is occurring for the next thirty thousand years.Thus it is ALWAYS on the cooling side of the line that make the snow and ice fields to grow.
dallas says:
September 16, 2012 at 5:52 pm
Leif, I clicked on the link in the post but for some reason the only parts I could read were links to your site. http://i122.photobucket.com/albums/o252/captdallas2/…
I don’t recognize that plot and don’t know what you clicked on and what you got, sorry.
sunsettommy says:
September 16, 2012 at 6:45 pm
Thus it is ALWAYS on the cooling side of the line that make the snow and ice fields to grow.
Yet today is also below that line and it is warming [AKA Global Warming]
Dr. Svalgaard writes,
“Yet today is also below that line and it is warming [AKA Global Warming]”
Your reply indicate that you are willing to ignore the fact that LONG TERM cooling is in the chart for the next 50,000 years.Since I used the same chart YOU brought up you will have to accept the 510 line as I pointed out that show cooling is the trend BECAUSE it is already below the 510 line from now one for a long long long time.
The last 1,000 years is a cooling trend too but who is paying attention to that? You or ……?
Since the Minoan Warming time the warming epochs have been around 350 years long and the Modern Warming is already about 340 years long since the bottom of the LIA that was in the 1670’s.
To continue along this line of thinking is that the last 4 main warming epochs in the Holocene have been about 1,000 years apart and last around 350 years.There is a decline from the days of the Minoan warming to now and still on line today.
The Minoan then the Roman then the Medieval and now the Modern warming are actually part of a long term cooling trend as shown by this Chart:
http://c3headlines.typepad.com/.a/6a010536b58035970c01287656565a970c-800wi
http://www.c3headlines.com/2009/12/are-modern-temperatures-unprecedented-us-govt-greenland-ice-core-research-finds-theyre-not-even-clos.html
John Kehr posted some nice charts too:
http://theinconvenientskeptic.com/wp-content/uploads/2012/01/Chap_8-Illustration_65-550×450.png
http://theinconvenientskeptic.com/chapters-8-10/
tallbloke says:
September 16, 2012 at 6:57 am
I’ll just add that it’s worth noting that 65N insolation didn’t drop as far as at the end of the last half dozen or so interglacials, we’re already past the low point, and the Holocene is already longer than several past interglacials. Also, 65N insolation is not the only important factor. Eccentricity times well with the periodicity of glacial interglacial cycles.
We might be in luck. I hope so, even if it means we just keep getting warmer and the AGW theorists carry on holding sway with their mumbo jumbo. I’d rather put up with bad science than the onset of a glacial.
Hopefully, the shorter term multidecadal drop in T both David and I (and many others) expect from around 2014 onwards will put paid to the AGW meme forever anyway, once nature has performed the crucial experiment for us.
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as a layman in looking at things, this has the appearance of an egg sitting a top a pointy wall and just the slightest breeze will send it crashing… now if a moderate to large volcano goes off it could be just enough breeze to send it over…. with the warming factors gone and cooling already started in the oceans it will be a rather rapid fall into cold…
everyone is such a bearer of good news… man does not far well in cold…viruses and other things grow well in cool and wet climates… just a bad recipe for man in general..
@ur momisugly mike g on September 16, 2012 at 6:00 pm:
Among other things, if we’re approaching that as a serious proposal, the foil doesn’t have to match the existing contours. Flat sections can be placed on supports oriented towards the Earth. Imagine the Moon covered in millions of reflectors. It can be a focusing array directed at the Earth in general.
That’ll make for a cyclical signal, nothing but reflected Earth-shine for new moon, and rather bright nights for full moon, about nine times as bright.
Hey, if a few extra watts per square meter in retained longwave infrared is enough for global warming, leading to predicted catastrophic global warming, the contribution from a shiny Moon directed at Earth should be good for something, right?