Paleoclimatologists Rock -Two million years of radical climate change is significant.
David C. Greene writes:
“The smoking gun of the ice ages” is the title of an article in the Dec. 9, 2016 issue of Science, the journal of the American Association for the Advancement of Science. The author, David A. Hodel, is listed with the Laboratory for Paleoclimate Research, Department of Earth Sciences, at Cambridge University in the UK.
Hodel cites a 40-year-old paper in Science, 194,1121 (1976). In that paper, Hays, Imbrie and Shackleton reported that their proxies for paleo sea surface temperatures and changing continental ice volumes exhibited periodicities of 42,000, 23,500 and 19,000 years, matching almost exactly the predicted orbital periods of planetary obliquity, precession and eccentricity. They also found that the dominant rhythm in the paleoclimate variations was 100,000 (±20,000) years.
Other climatologists have identified 20 glacial/interglacial oscillations over the past two million years with glacial parts of the cycles lasting about four times as long as the warm, interglacial parts. The last glacial maximum was about 18,000 years ago. We have been enjoying the present warm interglacial for about 12,000 years.
At glacial maxima, sea levels have been about 400 feet below present sea levels and sea surface temperatures about nine degrees C (14.4 degrees F) lower than present temperatures. The movement and conversion of 400 feet of ocean water to ice located in the higher latitudes required large and long-lasting influence from outside the Earth. The persistence and the magnitude of the above-described changes cannot logically be ascribed to mankind’s combustion of fossil fuels. Furthermore, in the terminations of the glacial eras, rising temperature preceded rises of CO2 by several centuries, absolving CO2 as the cause of the preceding temperature rise.
I cannot identify the cause(s) of the Earth’s quasi-repeatable climate excursions during the past two million years. However, the data provided by the paleoclimatologists makes sense to me as a physicist with three semester-hours of astronomy. My candidate for responsibility is an orbital influence on the amount of energy Earth received from the Sun as the Sun slowly danced around the center of mass of the entire solar system, with Jupiter being the weightiest of the Sun’s planetary dancing partners.
This post brings back good memories. I read the Hays, Imbrie, and Shackleton paper when it came out when I was a graduate student. Quite by extraordinary coincidence I was working with them two years later on the groundbreaking projects – CLIMAP and SPECMAP – that elaborated on their original work. They were excellent scientists. Imbrie brought mathematical techniques (factor analysis) to geological research. Shackleton did much of the isotopic analysis. Hays led the collaboration.
Just found this article from Dr. Linsky and Seth Redfield…
Open access article too, HB to me..
Visualizing the three-dimensional structure of the
local interstellar medium and possible physical
causes for this structure
J.L. Linsky, Redfield, S., and Schwarz, M.,
Journal Of Physics: Conference Series 767, (2016).
http://iopscience.iop.org/article/10.1088/1742-6596/767/1/012016/pdf
…Understanding the structure and properties of the LISM clouds is important, because the
LISM serves as an interface between the heliosphere and the Galactic interstellar medium,
providing physical insights concerning both. The Sun is located barely inside the Local
Interstellar Cloud (LIC) (see Figure 1), and the motion of the Sun through space will take
the heliosphere outside of the LIC and into either: (a) the adjacent G cloud, (b) an interface
between the LIC and G clouds, or (c) the highly ionized gas that may lie between the LISM
clouds. This transition will occur in less than 4000 years [8], perhaps far less.
M¨uller et al. (2006) [8] calculated the location of the termination shock, heliopause,
and bow shock for a wide range of interstellar densities, temperatures, and flow velocities that the heliosphere would see during its past and future trajectory through the inhomogeneous LISM.
For example, the passage of the heliosphere through a cloud with a neutral hydrogen density of 11 cm−3
rather than the present value of about 0.2 cm−3 would shrink the termination shock from about 90
AU in the upwind direction to only 14 AU. ……………
Irrelevant, as there are no such thick clouds in our stellar neighborhood.
“The answer my friend, is blowing in the wind, the answer is blowing in the wind.”
Density is only one factor.
Interstellar Wind Velocity and Direction(s) (more then one? arrival direction)
Interstellar Magnetic Field strength
Interstellar Temperature
Interstellar Density and composition at time
ETC….
There also would be other types of Interstellar Scale Type interactions.
Visualize Interstellar Scale Size Co Rotating Interaction regions or Counter Rotating Interaction regions. CIR’s located within and at boundaries and cloud collisions regions of Interstellar clouds. Whew, sounds breezy to me.
We encounter the small scale CIR’s on Earth from our Sun and is proportional to our Sun’s output. Galactic scale is significantly larger.
Density is only one factor.
It is the only factor as the distance to the heliopause is determined by the pressure balance between the solar wind and the interstellar medium which in turn depends on the density.
The hypothesis that the solar system displacement through the galaxy, both through the spiral arms in its rotation around the center of the galaxy, and through the plane of the galaxy, can explain both the apparent 150 Myr ice-age cycle and the apparent 27 Myr cycle in biological diversity is quite interesting, even if far from having strong support.
This is the essence of the 150 Myr ice-age cycle, according to Shaviv:
http://www.sciencebits.com/sites/default/files/pictures/climate/crcFig6.jpg
“Two extraterrestrial signals have the same periodicity and phase as two independent terrestrial records. Plotted are the period and phase (of expected peak coldness) of two extraterrestrial signals (astronomical determinations of the spiral arm pattern speed and cosmic ray flux reconstruction using Iron meteorites) and two paleoclimate reconstruction (based on sedimentation and geochemical records). All four signals are consistent with each other, demonstrating the robustness of the link. If any data set is excluded, a link should still exist.”
The paper you link also has an interesting conclusion:
Differences in UV radiation have also been proposed as causative agents mediating the solar variability effect on climate.
…”””For example, the passage of the heliosphere through a cloud with a neutral hydrogen density of 11 cm−3
rather than the present value of about 0.2 cm−3 would shrink the termination shock from about 90
AU in the upwind direction to only 14 AU”””…
14 AU would put the solar systems, “”termination shock, heliopause, and bow shock,”” between the Jupiter/Saturn system and the Neptune/Uranus system. What a mess that would/did create, sounds like the perfect, hail and brimstone scenario, mentioned by antiquities.
Except for two things:
There are no such dense clouds in the solar neighborhood and because the solar wind is supersonic the Earth would not know it.
It seems to me I keep seeing attempts to simplify causes for climate variations. This would appear to be a futile task given the volatile and chaotic nature of climate, atmosphere and oceans.
As far as I can see from the work of much smarter and more dedicated researchers than I, there are many factors involved in changes.
Some notes: (feel free to comment on any of them or tell my my arse has replaced my mouth… 😀
1. The Sun orbits the solar system barycenter which can be outside the solar surface when the gas giants congregate on one side.
2. The Earth of all the planets, specifically does NOT orbit either the Sun or the barycenter; instead the CoG of the earth Moon system is what orbits the solar system barycenter.
This means even on a small scale there are variations in distance to the Sun and thus incoming radiation/solar wind, especially when the Moon gets closer to the Sun that Earth.
3. Svensmark et al’s CLOUD effects magnify the changes in incoming energy by changing the lower cloud cover (from GCR’s) and thus the albedo. Thus a minor alteration in solar TSI can multiply the apparent effect for the planet.
4. The Earth is NOT a flat disk as used to simplify calcs for albedo etc. This causes AGW types no end of trouble as they claim ice at the poles has significant effects on albedo in relation to solar input, but seems to me, as soon as you use a globe instead of a flat disk, the albedo from the poles becomes close to irrelevant. This is because the incoming energy is at an angle-to-surface of 70º or more. i.e. most of it is going to ‘bounce’ from the surface rather than reflect directly back out..
You can sort of see this effect with false dawn at lower latitudes – the light from the approaching Sun reflects into areas before the Sun actually approaches the horizon as the true dawn.
5. Herndon’s georeactor seems to have come well beyond the ‘outlandish’ idea it was greeted as and is moving into mainstream. Thus we have an ongoing and renewing source of internal heat for Earth rather than a fading ’ember’ of a core steadily losing heat over the millennia.
9. There appears to be movement of heat regions internal to Earth that can bring more heat closer or further to various regions under the crust.
10. There are gravity ‘pulses’ that perturb the Earth as the larger planets (or nearer ones) approach and recede – these must have an effect and there are quite a few people linking earthquakes/vulcanism events to astro causes.
11. There is a magnetic ‘reconnection’ event occurring between Earth and Sun at what seems a weirdly significant timing – every 8 and a bit minutes. Given the Earth to Sun light time, this seems strangely synced – strange because it SHOULD be 16 and a bit to account for a dual trip effect. Just what this event does I don’t know but it is a strong indicator (IMO) that we cannot exclude either electrical or magnetic additions to the climate causes.
12. The solar system is awash in electrical energy from the solar plasma. So we live IN an electrical field so solar changes will have significant effects right throughout the system in an electrical and magnetic sense.
13. There are the longer term astronomical cycles such as Precession, Obliquity and Eccentricity. I have yet to see a refutation of the idea that Precession is a whole-of-system effect rather than a simple Luni/solar effect causing the Earth to wobble. It seems to me the reliability of certain meteor showers and the precision of Venus Transits argues the Precession cannot be only an Earth phenomenon.
If this is so, then the calculated effects of Milankovitch cycles are going to have a built in error.
With all of these and probably lots I haven’t thought of, it seems premature to say the least to be arguing Milankovitch and other cycles as if they are solely significant.
I guess it comes back to what I keep telling the true believers of the Church of AGW – you cannot model chaotic systems on binary computers. And just as they fail constantly in their prophesies from computer models, any attempt to define what is really causing climate change will have the same issues.
MarkMcD May 23, 2017 at 9:12 pm
…rather than a simple Luni/solar effect causing the Earth to wobble…
Just a comment on your wobble comment.
As Earth rotates there is a compressional effect at the N. Pole and an extensional effect at the S. Pole.
http://www.esa.int/var/esa/storage/images/esa_multimedia/videos/2016/05/changes_in_strength_of_earth_s_magnetic_field/15980573-3-eng-GB/Changes_in_strength_of_Earth_s_magnetic_field_medium.jpg
Because the mass at the S. Pole is greater, land, ice, water, and the Earth is ‘somewhat’ pear shaped, this contributes to Earth wobble.
http://www.esa.int/images/geoid_bumpy_RGB_L,0.jpg
The rotary lie detector disproves all of the above comments and theories. About 1 million years BP there was no ice anywhere on the planet. How to we know that? Vostok 3 stops about 850,000 yrs BP while still in solid ice yet Greenland is known to have a temperate climate (Ancient Biomolecules from Deep Ice Cores Reveal a Forested Southern Greenland Science, Eske Willerslev et al., 2007 July 6; 317(5834): 111–114. doi:10.1126/science.1141758). Vostok, by extrapolation, has about 150,000 years BP of time still to drill to reach bottom. Now that would be interesting in the core that could be recovered near the ice/basement interface. It would show spores of the day such as in Dye 3. Since ice formed in both locations there has been more or less constant build up of ice. In both locations, there has been no evidence of interference in the build up by any of the oscillations covered in the “Smoking Gun” article. There has of course been temporary build up of glaciers etc and that is where the article has some substance. These are quite separate events to what has taken place around Dye 3 and around Vostok 3. Perhaps the readers could consider the expanding and contracting earth theory to further explain these oscillations remembering that sea level rises and falls are of themselves anything but uniform events.
“About 1 million years BP there was no ice anywhere on the planet.” Now IRFM, would you be willing to take a rotary lie detector test about that statement you just made?
Over to you – and where was the ice of that age and the core evidence to support your claim. I just happen to be part of a profession which drills on good imagination (aka modelling) and has a success rate on greenfield projects of about 1:100. Call me a positive sceptic!
IRFM
Antarctica has been continuously glaciated for the last 12 million years.
>>About 1 million years BP there was no ice anywhere on the planet.
Complete nonsense.
Prior to the MPT a million years ago, there were many ice ages, but they were smaller.
And Antarctica has been covered in ice for millions of years. It is just that the maximum lifetime of the deep ice is about a million years – anything older than that is crushed, pressure-melted, and flows out to the sea.
R
hallelujah – at last thank you Anthony – I have to admit I was extremely upset when a common contributor to your blog – rubbished Milutin Milanković theory – he is my favourite climate scientist of the previous century. John Christy is my fav for this century.
Milutin Milanković took about 30 years to do the maths (astronomical calculations) before the advent of computers for such purposes and his theory has been backed up not only by ice core day but by deep sea sediment data – a few decades ago and since then – more current evidence strongly suggests obliquity is the biggest player of the orbital cycles and guess what folks?? obliquity is on the decrease at the moment – many science text books have it still at 23. 5 degrees – it is now without question at 23.4 degrees and decreasing – which means the seasons will become less severe and all research is suggesting – another ice age is coming but not for many thousands of years yet!! so I suggest enjoy the warming because there will be hell on Earth as land that is used at present to grow crops becomes covered in up to 1.5 and some kilometres thick of ice as was the case (lots of sci evidence for this) during the last ice age!!
data not day = sorry
Not aware of anyone claiming otherwise.
Again, this is not disputed by the climate science community. CO2 didn’t cause the termination of the glacial maximums. CO2 only became important as a warm forcing on climate once thawing and ocean out-gassing allowed sufficient quantities of it to re-enter the atmosphere. The initial cause of the thawing is generally believed to be the very orbital cycles discussed in the article.
My report at:
https://wattsupwiththat.com/2016/12/16/climate-change-debate-latest-results/
described the application of advanced statistical analysis to the relationship between the monthly atmospheric CO2 concentration from the Mauna Loa Observatory and UAH satellite lower troposphere temperature for the Tropics Land zone. There was a positive correlation between the temperature and the annual rate of change of CO2 concentration with very high statistical significance. However, for the temperature relative to the CO2 concentration time series, there was a minute correlation coefficient with significant probability that the coefficient was zero.
The result was supported by the same analysis applied to the atmospheric CO2 data from Macquarie Island in the Southern Ocean. To these results I can now add the analysis the CO2 concentration time series for the Mount Waliguan Observatory on the Tibetan Plateau. Relative to the Northern Extension satellite temperature zone, the Land component gave a correlation coefficient of -0.12 with a 3% probability that the coefficient was zero and, for the Ocean component, the coefficient was -0.13 with a 2.1% probability that the coefficient was zero. Once again this result is the complete opposite to the IPCC claim. For the temperature relative to the annual rate of change of CO2 concentration, the maximum correlation of 0.14 arose with respect to the Tropics Land temperature zone with 1.3% probability of a zero coefficient for a two month lag of the CO2 annual rate of change relative to the annual average Tropics Land temperature.
Additional confirmation has been found in the auto-regression function for the Tropics Land and Ocean satellite lower troposphere temperature series and the same function for the Mauna Loa annual rate of change of CO2. All have identical auto-correlation functions showing that they have arisen from the same cause. The first maximum in the periodicities was at 45 months which is the period for the El Nino maxima. Another was at 135 months corresponding to the Sun cycle driven by the 11.86 year orbital period for Jupiter. The source of other periodicities, for example 90, 180 and 270 months, remain to be discovered.
In conclusion, increased atmospheric CO2 concentration does not cause an increase in temperature. It is the level of temperature that controls the rate of change of CO2 concentration. As the Equatorial zone has the highest average temperature, it must produce a major portion of the atmospheric CO2. That concentration will continue to increase until the temperature reaches a critical level where the rate falls to zero. This could be zero degrees Centigrade at which point water freezes and is no longer available to life forms. That explains the 700 year lag between the temperature maximum preceding an ice age and the consequent maximum in the CO2 concentration. The auto- correlation function indicates that it is the Sun’s radiance, modulated by the tidal effect of the rotating planets, that drives the change in the Earth’s atmospheric temperature.
” In conclusion, increased atmospheric CO2 concentration does not cause an increase in temperature. It is the level of temperature that controls the rate of change of CO2 concentration. …. ”
I fully agree and support that statement.
Thank you rishrac. At least I now know that there is one other person that agrees with my findings.
Of equal importance is my statement that the Tropics temperature and the rate of change of CO2 concentration have the same auto-correlation function. That means that neither parameter responds to human activity as human activity has not altered with the periodicities revealed by the auto-correlation function, at least, not to my knowledge.
It is also pertinent to the comment by Frederick Michiels May 24, 2017 at 5:35 pm in that the auto-correlation function has revealed the periodicities that he suggests combine together to bring about ice ages.
If you look back at some of my earlier posts concerning topics of co2, I have clearly stated that co2 follows temperature. The reason is that, at least up until March 2015, ( and it was in response to a poster that said something about the rate of increase after 1998 ) I downloaded the co2 ppm per year and the the temperature change per year from NOAA right into a spread sheet. I was really surprised that even with this very simplistic method, nowhere near the level which you have done, the co2 levels per year varied with temperature. NOAA has been hard at work revising those numbers since. Also, one of the other things I also discovered was that co2 levels from peak ppm to peak ppm follow solar activity. It also follows cosmic ray activity as well. It is very clear from the record that it does so. there was a blip in cosmic ray activity in 1962/1963 and co2 ppm per year followed. Which one followed which, temperature or cosmic ray affecting temperature or something else, or a combination remains unknown. Since I let this be known, NOAA has adjusted the co2 ppm per year, 2005 is a good example of refuting findings by changing the data. 2005 the ppm for that year was 2.52 in 2015, the last time I looked it was 3.10 for 2005 and the temperature data set had changed as well.
There has been some excellent work done on the periodicity. I gave someone here a +1 on saying three when combination are either constructive or destructive in bring about an ice age. There is also evidence that supports close encounters with comets ( Malaga bay) for rapid cooling. They’ve also alluded to a property that I’ve seen physically in that ( and I didn’t know that it was written in ancient Greece) that the earth’s way of rotating around the sun changes. One pole faces in and the other out, so that there are 2 springs and 2 winters in one hemisphere, and 2 summers and 2 falls in the other.
Thank you for publishing your research. It really helps an argument when researchers determine the same thing by 2 different methods and independently.
If sea level is 120m lower and we have a landbridge from Australia to Asia and between America and Russia doesn’t that change ocean circulation? Tropical oceans oceans must get warmer also because of increasing atmospheric pressure.
Willis,
Could you comment about:
An Engineer’s Explanation of Climate Change
https://wattsupwiththat.com/2017/04/09/an-engineers-explanation-of-climate-change/
This is a slightly off topic comment, but this seems the proper forum. In looking at the contribution of volcanos to CO2 it seems that the contribution is in the range of 0.6 billion metric tons of CO2 per year. This is in the range of 2% of the current human contribution. A significant and uncertain portion of that comes from undersea volcanos.
The thought is how does this contribution function during the ice ages. In the cold ocean water is the CO2 and methane (as methane hydrate) retained (accumulated) in the ocean (deep ocean) until some level of warming occurs. I could then be released as a surge (over hundreds of years) when the saturation pressure equalizes with the increases ocean temperature.
A way to check would be to calculate the quantity of CO2 added to the atmosphere during the end of ice age warming (presumably from the oceans); and see if this sort of balances with the contribution of undersea volcanos over the course of a couple 100,000 years. I would think that significant methane volumes would also be released.
Dr. Isvalgaard, Good day sir and thank you for all that you do. Regarding this (orbital influence on the amount of energy Earth received from the Sun as the Sun slowly danced around the center of mass of the entire solar system. No, that is not the reason), you said the following, above. “Planetary perturbations [mainly Jupiter’s] alter the orbital parameters of the Earth leading to different regions receiving different amounts of TSI. This has been discussed ad nauseam here on WUWT. Go look and you’ll find.” I once read a quote that said “the problem with the world is that ignorance is cock sure and intelligence is full of doubt.” While I respect your research and what you have brought to the table of knowledge on the subject, I can’t help but ask if you are closed to the idea that perhaps both theories have a part in Earth’s Climate?
if you are closed to the idea that perhaps both theories have a part in Earth’s Climate?
The first one will not work as the sun [like the earth] is in free fall. You don’t feel you are moving, so neither does the sun. The second one has observational support although there is debate about the details.
Milankovitch Theory is a Zombie Theory
Come on man. I am bored to tears talking endlessly about zombie theories. We likely need a thread per Zombie theory to explain why the Zombie theory is a Zombie theory which can be referred to.
The smoking gun, is solar cycle changes cause the cyclic changes to the earth (geomagnetic field changes that correlate with climate change, volcanic changes that correlate with solar cycle changes, cyclic abrupt climate changes, and sea level).
The problem is not if the sun causes what is observed but how the sun causes what is observed.
P.S. There are more than 200 astronomical anomalies and paradoxes that are directly connected to how the sun is causing the weird cycle changes on the earth.
First Milankovitch’s Zombie Theory
https://en.wikipedia.org/wiki/Milankovitch_cycles
Milankovitch cycle Problems (How many ‘problems’ are required to stop a Zombie theory?)
1) 100,000 year problem
2) Southern Hemisphere cools cyclically at the same time as the Northern Hemisphere
https://www.sciencedaily.com/releases/2004/03/040319071426.htm
3) Stage 5 problem (Causality Problem)
4) Effect exceeds cause
5) The unsplit peak problem
6) The transition problem
http://en.wikipedia.org/wiki/Milankovitch_cycles#/media/File:Five_Myr_Climate_Change.svg
7) Identifying dominant factor
8) The Younger Dryas Problem
The planet when from interglacial warm to glacial cold at the time of the Younger Dryas abrupt cooling event 11,900 years BP, at a time when summer solar insolation at 65N was maximum (the YD is another observation that supports the assertion that Milankovich’s theory is pure Zombie) 70% of the cooling occurring in less than a decade.
The Younger Dryas abrupt cooling event lasted for 1200 years. An impact or a volcanic eruption will cool the planet for a few years, not 1200 years.
9) Periodicity Paradox. The small, large, and super large climate events all have the same periodicity (1400 years with a beat frequency of plus or minus 400 years) which points to the same cause.
Another hint to the cause is there is solar cycle change evidence in the proxy which correlate with each and every climate change event.
The periodicity paradox rules out internal earth mechanisms which are ‘chaotic’ (William: Volcanic eruptions for example or changes to ocean currents) as the cause of massive cycle climate changes.
http://www.agu.org/pubs/crossref/2003/2003GL017115.shtml
10) And so on.
This is what we are trying to explain.
Greenland ice temperature, last 11,000 years determined from ice core analysis, Richard Alley’s paper. William: The Greenland Ice data shows that have been 9 warming and cooling periods in the last 11,000 years. There was abrupt cooling 11,900 years ago (Younger Dryas abrupt cooling period when the planet went from interglacial warm to glacial cold with 75% of the cooling occurring in less than a decade and there was abrupt cooling 8200 years ago during the 8200 BP climate ‘event’).
http://www.climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20with%20CO2%20from%20EPICA%20DomeC.gif
http://www.hidropolitikakademi.org/wp-content/uploads/2014/07/4.gif
http://www.climate4you.com/images/VostokTemp0-420000%20BP.gif
Another hint to the cause is there is solar cycle change
There is no evidence [or physical explanation] for your “solar cycle change”. And the influence of solar activity is so minute anyway that it barely rises over the noise.
the whole issue is it’s not the milankovich cycle, it’s not the sun cycle, it’s not obliquity,…. each on their own are not able to drive enough to explain the ice age
however when you take all these drivers together as a timed harmonic event (just as how you look at a sound that’s just a resulting wave formed by a combination of sinus waves of varying phases amplitudes, intensities and frequencies) then it becomes interesting….
to me ice age/interglacials always resembled a lot like this basic “sawtooth sound”
http://www.co-bw.com/Images_Audio/HarmonicSynthesis.gif
Of course sound is a static set of variables that repeat with very static known “drivers” while climate also has a noise and dynamic aspect (no sawtooth wave of the interglagial/glacial cycle is the same), however something is producing a 100Kyr main “driver wave”. unlike with sound in climate this can be a combination of climate drivers that “join and then diverge to join then again together.
what does sound and climate have then in common? Well just add a strong random noise to that sound drawing and it will become pretty similar to the temp graph. add a random slight “pitch change” and you even get near to the iregularity of the temp graph.
so add it all up: Milankovich cycles, solar cycles, obliquity, precession,… (do we even know them all? i’m sure we don’t) and add the noise of volcanic eruptions, iregularities in these cycles,……
See this as looking at it from a totally different angle, but something is driving this and the “shape” of the wave is referring to what order and in which way these drivers do amplify/converge with each other and subtract/diverge with each other to create the ice age cycle with it’s Oescher Dansgaerd events etc….
to me it’s not “just the sun, or just the Milankovich cycle or just (fill in what applies) but a combination of how they “work together as a dynamic system”
imho we even don’t know how these work we just start to scratch the surface of it but thats why i find these discussions here so fascinating….
If you scratch the surface enough, you ruin the sculpture.
Sharp cycles have sharp drivers and restoring forces. Those seem to be missing in the climate.
>>100,000 year problem.
There is no 100,000 year problem, because thre is NO 100,000 year cycle. The recent cycle is 90 ky and 115 ky, and it is comprised of multiple precessionary cycles.
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>>Southern Hemisphere cools cyclically at the
>>same time as the Northern Hemisphere.
Because the climate is controlled by albedo, not CO2. And the large land masses and therefore ice sheets (and therefore most of the albedo) are all in the northern hemisphere.
.
>>Stage 5 problem (Causality Problem).
Not sure what you mean. The Eemian appears to be coincident with a NH precessionary increase.
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>>Effect exceeds cause.
Because there are feedback effects. The feedback-forcing provided by albedo is in the order of 200 w/m2, when measured regionally, which is much greater than orbital forcing on its own. So albedo trumps Milankovitch, and it trumps CO2.
.
>>The unsplit peak problem.
Because albedo trumps orbital insolation variation. The albedo feedback effect is so intense that some precessional (and obliquity) peaks have no effect whatsoever (all the increased insolation is reflected back to space). Orbital forcing (Milankovitch) can only have an effect when the ice sheets are impregnated with dust, and have a lower albedo.
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>> The transition problem.
The MPT was caused by the steady cooling of the climate passing a threshold, and allowing albedo effects to become dominant. Thus obliquity was superceded by precession as a modulating factor. The reason for the continuous cooling of the climate over the last 50 odd million years is not entirely understood. Possibilities include the slow cooling of the oceans, or the rise of the Himalaya (and its albedo) reducing total absorbed insolation.
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>>Identifying dominant factor.
The dominant orbiting factor was obliquity, but is now precession (except when eccentricity is low, and then obliquity becomes dominant again).
.
>The Younger Dryas Problem
The YD may well have been due a meteor impact, and so is anomalous. Please see this short article:
The YD, the Carolina Bays, and the Destruction of North America.
https://www.academia.edu/20051868/The_Carolina_Bays_and_the_destruction_of_North_America
.
See my paper on the modulation of ice ages via albedo and dust, which explains everything:
Modulation of ice ages via precession and dust-albedo feedbacks.
http://www.sciencedirect.com/science/article/pii/S1674987116300305
Ralph
You are asking the right questions IMHumbleO. The unintended red herring is obliquity – that it is restricted to ~22-24deg. NO. Its mean floats. Ask why both poles change temps at the same time, but opposite to equator. At ~2345bce there is an abrupt increase at Gisp2/Vostok but a drop at Kilimanjaro (remember the fast frozen weeds at Quelccaya). There are other issues also.
Reply further down pls
Why are we still asking the question “how can such a weak forcing as obliquity be responsible for pacing the interglacials”, over the last million years following the mid Pleistocene revolution (MPR)? The answer is obvious from the above figure which shows in parallel all the Milankovich cycles. Two important Milankovich drivers, both much stronger than eccentricity per se as climate forcers – the summer insolation at 65degN and precession, both directly correlate with eccentricity in their amplitude modulation. By this I mean the way that their respective wavetrains get fatter and thinner, i.e. alternate between smaller and larger amplitude. High amplitude eccentricity peaks coincide with high amplitude oscillations of both the above mentioned cycles, and ditto for the low amplitude eccentricity peaks.
Now as Javier made clear in his recent post at Judith Curry, especially in figure 35:
https://judithcurry.com/2017/04/30/nature-unbound-iii-holocene-climate-variability-part-a/
the proximal driver of the timing of interglacials, but with a 6,500 year delay. In figure 35 of Javier’s article, there is a temperature peak at every single one of the (6,500 year lagged) obliquity peaks. No exceptions. However, of course, not all those peaks are interglacials.
Only the obliquity peaks which come close to eccentricity peaks result in a full interglacial.
And no – O ye of the 7-second-goldfish-memory – before you start replying that eccentricity can’t be strong enough to force the interglacial, remember what I just pointed out: every eccentricity peak coincides with peak amplitude in both 65N summer insolation and precession. (Those two are of course directly related to each other, I get that).
It isis when a 6,500-year-lagged obliquity peak comes closest to the combined eccentricity / 65N summer insolation / precession amplitude peak, that you get an interglacial.
What would you expect to happen when the lagged obliquity peak falls halfway between the amplitude peaks of eccentricity / 65N insolation / precession? A double-headed interglacial. And that is exactly what happens. At 200,000 and 600,000 years ago, such double-headed interglacials occured.
The above relationship completely and sufficiently explains when interglacials occur. It also helps understand why the MPR happened, when the pacing of interglacials changed from 41,000 years – i.e. directly following lagged obliquity, to an apparent, approximate 100,000 year pacing. Prior to the MPR, lagged obliquity alone was strong enough to initiate an interglacial every time. However as the Pleistocene glaciation deepens, there appears to be a declining sensitivity of the climate’s glacial-interglacial system to Milankovich forcing (which itself remains essentially unchanging). Thus after the MPR, an obliquity peak (lagged) alone was no longer sufficient to initiate an interglacial. It needed the added impetus of amplitude peaks of 65N insolation and precession – both of which are in step with eccentricity.
It is also obvious why 65N insolation and precession amplitude peaks should coincide with eccentricity peaks, since eccentricity directly affects both these cycles. High eccentricity will amplify the insolation effect of precession as the earth is brought closer to the sun at perihelion.
Finally, why the 6,500 year lag in the dominant interglacial forcing of obliquity which Javier showed incontrovertibly? The reason for this is important. It takes 6,500 (not 800) years of increased solar heat input to the oceans before the oceans themselves, by their dynamics of circulation and heat transport, bring about climate warming and interglacial inception.
Climate change comes from the ocean, and follows the ocean’s rhythm. It’s a slow one, and can’t be rushed.
Correction (just after JC link):
the proximal driver of the timing of interglacials, but with a 6,500 year delay, is obliquity.
Another correction in the opening sentence:
“Why are we still asking the question “how can such a weak forcing as
obliquityeccentricity be responsible for pacing the interglacials”What has been overlooked in all of the discussion is that we have an example of what has caused glaciation and recovery in the past, and that is the Little Ice Age. This began with a VEI7 eruption in 1258, followed by an “unusual 50-year-long episode with four large sulfur-rich explosive eruptions, each with global sulfate loading >60Tg” (Miller, et al, 2012).
This quantity of sulfate aerosols would have caused global cooling for more than 5 years each (based upon the cooling resulting from the 1815 VEI7 Mount Tambora eruption, with about 50Tg of sulfate emissions). Other eruptions also occurred during the LIA, maintaining the cooling through “sea-ice/ocean feedbacks”, and glaciers advanced.
With demonstrated cooling from volcanic sulfate aerosols, periods of extensive volcanism in the past would NECESSARILY have had the same effect, and, when extensive enough, would have triggered the various Ice Ages, regardless of any solar cycles.
Cessation of eruptive periods would explain the observed rapid warming at the end of an Ice Age, with the suddenly less polluted air allowing sunshine to strike the earth’s surface with greater intensity.
William Astley, above, states that “an impact or a volcanic eruption would cool the planet for a few years, not 1200 years”, but periods of multiple eruptions could easily do so. Volcanism that formed the Deccan and Siberian traps, for example, reportedly lasted for thousands of years.
Burl
Look carefully at figure 35 in this article:
https://judithcurry.com/2017/04/30/nature-unbound-iii-holocene-climate-variability-part-a/
Every upward oscillation in temperature fits exactly with a peak in the degree of obliquity (lagged by 6500 years. Is obliquity causing volcanism? I don’t think so. It is well known that obliquity increases heat transport toward the poles and unlike the other Milankovich cycles, has the same warming / cooling effect on both hemispheres.
FWIW here is the corrected version:
Why are we still asking the question “how can such a weak forcing as eccentricity be responsible for pacing the interglacials”, over the last million years following the mid Pleistocene revolution (MPR)? The answer is obvious from the above figure which shows in parallel all the Milankovich cycles. Two important Milankovich drivers, both much stronger than eccentricity per se as climate forcers – the summer insolation at 65degN and precession, both directly correlate with eccentricity in their amplitude modulation. By this I mean the way that their respective wavetrains get fatter and thinner, i.e. alternate between smaller and larger amplitude. High amplitude eccentricity peaks coincide with high amplitude oscillations of both the above mentioned cycles, and ditto for the low amplitude eccentricity peaks.
Now as Javier made clear in his recent post at Judith Curry, especially in figure 35:
https://judithcurry.com/2017/04/30/nature-unbound-iii-holocene-climate-variability-part-a/
the proximal driver of the timing of interglacials, but with a 6,500 year delay, is obliquity. In figure 35 of Javier’s article, there is a high temperature peak at every single one of the (6,500 year lagged) obliquity peaks. No exceptions. However, of course, not all those peaks are interglacials.
Only the obliquity peaks which come close to eccentricity peaks result in a full interglacial.
And no – O ye of the 7-second-goldfish-memory – before you start replying that eccentricity can’t be strong enough to force the interglacial, remember what I just pointed out: every eccentricity peak coincides with peak amplitude in both 65N summer insolation and precession. (Those two are of course directly related to each other, I get that).
It is when a 6,500-year-lagged obliquity peak comes closest to a combined eccentricity / 65N summer insolation / precession amplitude peak that you get an interglacial. Every time.
What would you expect to happen when an amplitude peak of eccentricity / 65N insolation / precession falls halfway between two obliquity peaks? A double-headed interglacial. And that is exactly what happens. At 200,000 and 600,000 years ago, such double-headed interglacials occured.
The above relationship completely and sufficiently explains when interglacials occur. It also helps understand why the MPR happened, when the pacing of interglacials changed from 41,000 years – i.e. directly following lagged obliquity, to an apparent, approximate 100,000 year pacing. Prior to the MPR, lagged obliquity alone was strong enough to initiate an interglacial every time, regardless of where the other Milankovich cycles were at. However as the Pleistocene glaciation deepens, there appears to be a declining sensitivity of the climate’s glacial-interglacial system to Milankovich forcing (which itself remains essentially unchanging). Thus after the MPR, an obliquity peak (lagged) alone was no longer sufficient to initiate an interglacial. It needed the added impetus of amplitude peaks of 65N insolation and precession – both of which are in step with eccentricity.
It is also obvious why 65N insolation and precession amplitude peaks should coincide with eccentricity peaks, since eccentricity directly affects both these cycles. High eccentricity will amplify the insolation effect of precession as the earth is brought closer to the sun at perihelion.
Finally, why the 6,500 year lag in the dominant interglacial forcing of obliquity which Javier showed incontrovertibly? The reason for this is important. It takes 6,500 (not 800) years of increased solar heat input to the oceans before the oceans themselves, by their dynamics of circulation and heat transport, bring about climate warming and interglacial inception.
Climate change comes from the ocean, and follows the ocean’s rhythm. It’s a slow one, and can’t be rushed.
Slightly off-topic but I have a question for the physicists here
Please go to : http://www.remss.com/measurements/upper-air-temperature
Scroll down to temperature records since 1980 and observe charts showing:
Lower troposphere: 0.135 K/decade
Lower Tropospheric Stratosphere: – 0.258 K/decade
What is going on guys?
I am a Seeker (of truth) , not a skeptic
Regards
M
Guys,
This is all explained here:
https://wattsupwiththat.com/2017/04/09/an-engineers-explanation-of-climate-change/
It seems to me that precession, obliquity and eccentricity will have an affect upon ocean currents, wind patterns, El Niño, la Nino, and jet stream patterns. Would this not also affect weather and thus, to some degree, climate?
Figure 10 in Trenberth et al 2011jcli24 is typical of the so called atmospheric heat or energy balances which show 342 +/- W/m^2 entering perpendicular to the entire surface of the ToA, Top of Atmosphere. This models the earth as a ball suspended in warm fluid evenly heated in all directions. There is no consideration of day or night, aphelion or perihelion, tropospheric thickness, or the oblique incidence on a spherical surface. This value begins with the TSI, total solar irradiance, delivered by the expanding solar photosphere (3.847 E26 W) to the spherical surface of an average orbital distance of 1.496 E8 km yielding a value of 1,368 +/- W/m^2. A sphere of radius r has four times the area of a disc of radius r so 1,368 / 4 = 342 W/m^2.
As pointed out above the earth’s orbit is not circular, but elliptical and the difference in TSI between perihelion, closest and 1,423 +/- W/m^2, and aphelion, farthest and 1,323 +/- W/m^2, a total annual fluctuation of 90 W/m^2. But there is a second consideration, the 23.5 degree tilt of the earth’s vertical axis which drives the seasons. When the tilt is away from the sun it is winter in the northern hemisphere, summer in the southern hemisphere. When the tilt is towards the sun it is summer in the NH and winter in the SH. At this point in the Malinkovitch cycle the NH winter occurs near perihelion. So the coldness of the away tilt is balanced by the hotness of the closer orbit. This will change.
When the sun is directly overhead TSI at ToA delivers its full amount, but because of the oblique angle at other locations the TSI on a horizontal surface is reduced. Those who design and install solar panels are well aware of this.
At 40° N latitude and winter solstice the sun is 26.5° above the horizon and the TSI on a ToA horizontal surface is 630.5 +/- W/m^2.
At 40° N latitude and summer solstice the sun is 73.5° above the horizon the TSI on a ToA horizontal surface is 1,268.5 +/- W/m^2.
The total TSI variation on a ToA horizontal surface from winter solstice to summer solstice is 638 +/- W/m^2.
A TSI fluctuation of 638 W/m^2 and the only difference is summer and winter which the earth and mankind have survived every year for millions of years. The 2 W/m^2 and even the RCP 8.5 W/m^2 of IPCC models don’t seem all that significant.
And the notion that this 2.0 or 8.5 W/m^2 is disturbing some marvelous Zen balance maintained for millennia is religious dogma, not science.
The problem with the straight Milankovitch theory, is the missing ice ages over the last million years.
The periodicity of recent ice ages varies from 90 kyr to 115 kyr, which means that whether you champion obliquity or precession there are missing ice ages. No theory of ice age modulation can be complete, if those missing ice ages are not accounted for.
I accounted for this strange periodicity via albedo and dust. It is a theory that has stood up to questioning and has not been falsified.
Modulation of ice ages via precession and dust-albedo feedbacks.
http://www.sciencedirect.com/science/article/pii/S1674987116300305
.
Abstract
We present here a simple and novel proposal for the modulation and rhythm of ice-ages and interglacials during the late Pleistocene. While the standard Milankovitch-precession theory fails to explain the long intervals between interglacials, these can be accounted for by a novel forcing and feedback system involving CO2, dust and albedo. During the glacial period, the high albedo of the northern ice sheets drives down global temperatures and CO2 concentrations, despite subsequent precessional forcing maxima. Over the following millennia more CO2 is sequestered in the oceans and atmospheric concentrations eventually reach a critical minima of about 200 ppm, which combined with arid conditions, causes a die-back of temperate and boreal forests and grasslands, especially at high altitude. The ensuing soil erosion generates dust storms, resulting in increased dust deposition and lower albedo on the northern ice sheets. As northern hemisphere insolation increases during the next Milankovitch cycle, the dust-laden ice-sheets absorb considerably more insolation and undergo rapid melting, which forces the climate into an interglacial period. The proposed mechanism is simple, robust, and comprehensive in its scope, and its key elements are well supported by empirical evidence.
1. Introduction
Since the discovery of ice-age cycles almost two centuries ago, a large amount of geological evidence has been assembled from a variety of sources, and many different hypotheses have been advanced to account for their approximate 100 kyr periodicity and asymmetric, saw-tooth temperature response. Improved calculations of Milankovitch insolation cycles and greater precision of Antarctic ice-core records demonstrate that each major deglaciation coincides with maximum summer insolation in the northern hemisphere. And yet many of the other insolation maxima only trigger minor warming events, and so interglacials only occur after four or five insolation cycles. No generally accepted explanation exists for this peculiar intermittent climate response, and any comprehensive explanation for ice-age modulation and periodicity has to be able to explain this anomaly.
The answer to this conundrum can be found in a novel reanalysis of the effects of decreasing atmospheric CO2 concentrations during an ice-age. Ice age CO2 reductions coincide with an increase in ice sheet extent and therefore an increase in global albedo, and this should result in further cooling of the climate. But what actually happens is that when CO2 reaches a minimum and albedo reaches a maximum, the world rapidly warms into an interglacial. A similar effect can be seen at the peak of an interglacial, where high CO2 and low albedo results in cooling. This counterintuitive response of the climate system also remains unexplained, and so a hitherto unaccounted for agent must exist that is strong enough to counter and reverse the classical feedback mechanisms.
The answer to both of these conundrums lies in glacial dust, which was deposited upon the ice sheets towards the end of each glacial maximum. Previous research has considered two effects of this aeolian dust on the glacial climate: the increased albedo of atmospheric dust cooling the climate, and the mineral fertilization of marine life reducing atmospheric CO2. But both of these effects would result in a cooling feedback, and therefore provide no explanation for the interglacial warming that appears to result from dust deposition. In great contrast to these explanations it is proposed here that during the glacial maximum, CO2 depletion starves terrestrial plant life of a vital nutrient and causes a die-back of upland forests and savannahs, resulting in widespread desertification and soil erosion. The resulting dust storms deposit large amounts of dust upon the ice sheets and thereby reduce their albedo, allowing a much greater absorption of insolation. Up to 180 W/m2 of increased absorption can be provided to the northern ice sheets, when calculated seasonally and regionally instead of annually and globally.
This dramatic increase in insolation and absorption results in melting and dissipation of the northern ice sheets, and the establishment of a short interglacial period. Ice ages are therefore forced by orbital cycles and Milankovitch insolation, but regulated by ice-albedo and dust-albedo feedbacks. And the warming effects of dust-ice albedo are counterintuitively caused by a reduction in global temperatures and a corresponding reduction in CO2 concentrations. And while this proposal represents a reversal of conventional thinking it does explain each and every facet of the glacial cycle, and all of the many underlying mechanisms that control its periodicity and temperature excursions and limitations.
Ralf
What do you mean by “ice age”? The whole Quaternary? Or just an interval between interglacials?
There are no “missing ice ages”. I return to the figure 35 of Javier’s recent Holocene post at JC (it didn’t have 35 figure btw – just a number):
With the 6,500 year lag, every single temperature peak correlates with an obliquity peak. And why are some tall and some short? The tall ones which are called interglacials were the ones coinciding with the eccentricity / 65N max summer insolation / precession. Resonance, if you like.
I do think your glacial maximum dust findings are important and valid, especially insofar as they point to CO2 starvation.
But glacial-interglacial timing needs no atmospheric deus-ex-machina (dust, volcanos, cosmic magnets, CO2, bolides, etc…). It’s the oceans.
The 6,500 year delay which Javier showed is incredibly important. Think about what it means. What else other than ocean heat dynamics could account for it?
>>There are no “missing ice ages”.
The obliquity maxima 450, 370, 170, and 50 kyr ago did not produce interglacials. Javier has never explained the missing interglacials, and until he can do that the theory of obliquity influence is wrong.
And the obliquity maximum 250 ky ago is completely misaligned with the interglacial. Again, there is a failure here to acknowledge the role of precession, because this interglacial is aligned with precession, not obliquity.
Javier also has a habit of using Huyber’s marine sediment ice-age chronology, which is pure guessworks and should not be used in Palaeoclimatology.
R
Ralf
The obliquity maxima 450, 370, 170, and 50 kyr ago did not produce interglacials. Javier has never explained the missing interglacials, and until he can do that the theory of obliquity influence is wrong.
The whole point of my post was that precession and 65N summer insolation modulate the response of the glacial oscillator to obliquity. I don’t think you read more than a few words of it.
I’ll say it for the 4th time. With the 6,500 year lag, every single temperature peak correlates with an obliquity peak. And why are some tall and some short, some almost nonexistent ? The tall ones which are called interglacials were the ones coinciding with the eccentricity / 65N max summer insolation / precession peaks. Resonance, if you like.
Again, there is a failure here to acknowledge the role of precession
No there isn’t. In my post I write the word precession lots and lots of times. Alongside 65N summer insolation and eccentricity. My posts are not excessively long, please read them if you wish to comment.
Precession modulating obliquity with. 6500 year lag, explains perfectly all thr glacial-interglacial oscillation of the last million years and probably further back as well.
Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession. Precession.
O crap
Or It’s the increased volcanic activity from the Suns graviational oscillations you don’t consider, not the atmosphere, as the main effect, solar irradiance may also play a part as the radiation variation is the same as the graviational, +/- 30% or so pa.
It’s so obviously the oceans that hold the majority of the heat. How does solar variation affect that heat content during a an ice age cycle, and, in particular how does an eccentric orbit create such rapid, geological time step function, as oceanic warming, if it isn’t gravity working on the viscoelastic tectonics and our nuclear reactor core that cooks up the magma for redistribution? I suspect that is far more powerful than solar irradiance variation as an effect. Especially now I know about IO and Venus, and the role of tectonics in recycling CO2 from volcanoes, w/o which tectonics it is now said we would be Venus..
Also the solar radiation effects when closer and futher away must largely cancel each other out on total irradiance pa, whereas the gravitationally induced rock movements must increase, doesn’t net out. Because this such an obviously more powerful effect in term of heat content and gross energy in molten rock, delivered mostly directly to the high capacity long term ocean heat sinks for delivery to land by weather and directly by sea. Model that! Evidence would help such a hypothesis.
FIrst of all: Has anyone done a study of the movement of tectonic plates across ice ages, to see if movement varies cyclicy and in a correlated manner?. Is there a study of volcanic activity on land before an interglacial, at the end of an ice age?
I’m going to do the David MacKay back of the envelope maths on the incremental ice formation and melting involved in a typical ice age and compare to the magma flow required into the oceans to cause that, compared to what we think leaks out the various holes now.
Basically how much magma at 1200 degrees and the known thermal capacity of the rock will melt that much ice at the latent heat of ice plus a bit, Not that hard. Does the answer seem credible as an ibcrease in magma flow to the surface? Obviously weather can affect whether there is enough heat to complete the process to the temperature we expect of an interglacial, if the whole process is a bit marginal. But this is a hammer blw, as already suggested elsewhere. Just not binary on the return to long term stable ice age, sawtooth with noise.
But I’m not that clever. What I do see are relative energy levels between the various supposed cause and effect, and the simple facts that the effects that end ice ages are sudden, massive and must come from warmer oceans. How? – peak of MIlankovitch cycle is a good smoking volcano, doesn’t have to be precise.
Just the scale of relative effects and the new science on space volcanoes in the solar system means I now think looking at the atmosphere suffers from a serious failure to “organdise” a search. “Organdise”, said Christoper Robin, “is when you have a search, but you don’t all look in thsame place”. For me, it seems climate science is doing just that, looking at the relatively weak symptoms of the atmosphere as causes, modelling the noise using almost meaningless numerical models as “science” that they can force to correspond to the old dat at and forecest a tiny bit into the future, badly.
Yet the real cause may be left mainly unstudied, as it doesn’t fit the rhetoric, the tunnel vision climate atmospheric model led agenda, the subsidies for renewables that fund all this but make CO2 emissions worse in fact, etc., or simply the narrow speciaisation of the scientists turned priestsfor money and fame, and their unknowing but faithful believers. Just IMO. Your climate may vary.
Need to do some numbers. Where is that envelope?
Climate science is chock full of urban legends. Urban legend theories are theories (typically connected to a Zombie mechanism) which are repeated when there is obvious data and logic that supports the assertion that the theories in question are completely incorrect, not part of the solution.
Zombie theories block the solution to the problem.
1. The discrete thermal halone ocean conveyor theory has been proven incorrect by ocean float data. The discrete thermal halone conveyor started with a picture that Wally Broeker included in a paper without proof. Wally later in an interview stated that he was only presenting a hypothesis. Ocean float data shows only 8% of the flow in the North Atlantic follows the Broeker conveyor path. Therefore changes in the fresh water flow cannot interrupt the North Atlantic drift current and changes in the North Atlantic drift current do not affect ocean current flow in the Southern Hemisphere.
2. Basic analysis shows the heat transferred by the North Atlantic drift current is three times less than the heat that is transfer from summer warming of the North Atlantic ocean. A complete interruption to the North Atlantic drift current therefore cannot cause the cyclic warming and cooling of Europe and Greenland Ice sheet.
3. There is in the paleo record warming and cooling in the Southern Hemisphere that is simultaneous with the warming and cooling in the North hemisphere. If ocean currents where the cause of the warming there would be roughly a 1000 year lag.
4. When the Southern hemisphere, the Greenland Ice Sheet, and the Northern hemisphere warm, the Antarctic ice cools. This phenomenon is called confusingly the Polar see-saw (see Svensmark’s attached paper). The Antarctic ice sheet cools as the albedo of that ice sheet is greater than the albedo of clouds. Therefore, an increase in cloud cover over the Antarctic causes warming of that ice sheet rather than cooling. The albedo of the Greenland ice sheet is less than the Antarctic ice sheet and the Greenland ice sheet is not isolated by a polar vortex and hence unlike the Antarctic ice sheet follows the temperature of the surround ocean.
http://www.sciencedaily.com/releases/2009/05/090513130942.htm
http://www.americanscientist.org/issues/pub/the-source-of-europes-mild-climate
http://www.atmos.washington.edu/~david/Gulf.pdf
This paper by Svensmark provides data and analysis to support the assertion that changes to the solar cycle causes the weird phenomena which is called the polar see-saw.
As I noted above the earth’s climate is cyclically changing with a periodicity of 1470 years plus/minus 500 years. Svensmark shows through the analysis of ice sheet bore hole temperature, that the cyclic change is effecting both hemispheres simultaneously.
http://arxiv.org/abs/physics/0612145v1
Ptolemy2:
You asked me to look carefully at Figure 35 in a cited Judith Curry post by Javier.
What is most obvious to me is that warming during maximum periods of obliquity is poorly correlated with these periods, Sometimes there is a large response, but most times, just a minor blip of decreased cooling.
If obliquity were a significant factor, there would be strong warming during each peak, and that does NOT happen.
Even the legend of the graph, that the drop of obliquity always terminates interglacials is not completely correct, such as for the MIS17, MIS13, and MIS7c peaks–close, but no cigar.
Historically, cooling due to large volcanic eruptions always occurs, and any effort to explain pre-historic temperatures MUST include their effects.
A friendly reminder, while every ice age does not end when obliquity reaches it’s peak of around 24.5 degrees, EVERY ice age begins when obliquity drops below 23.5 degrees on it’s way to the minimum of around 22 degrees. There are NO EXCEPTIONS to this, zero, none…
Whatever the prime driver of ice ages are, whatever the combination of factors are, we know with 100% certainty they begin when obliquity drops below 23.5 degrees. No amount of arguing the details changes the outcome.
You all have been warned, act accordingly and stop rearranging the deck chairs on the Titanic.
Migrate below the Wisconsin Ice Age line and you should be fine.
dscott:
You state that “EVERY ice age begins when obliquity drops below 23.5 degrees on its way to the minimum of around 22 degrees. There are NO EXCEPTIONS TO THIS”
Assuming that we are looking at the same graph, MIS17 began dropping before obliquity reached 23.5 deg, as did MIS13, the first drop in MIS7c, and the deepening of the ice age in the first unlabeled peak after MIS7c.
Fine points, but not quite what you had stated.
Another friendly reminder: Correlation does not always prove causation.
Burl
Ptolemy2:
You asked me to look carefully at Figure 35 in a cited Judith Curry post by Javier.
What is most obvious to me is that warming during maximum periods of obliquity is poorly correlated with these periods, Sometimes there is a large response, but most times, just a minor blip of decreased cooling.
If obliquity were a significant factor, there would be strong warming during each peak, and that does NOT happen.
Like Ralf you very obviously did not read more than one or two words of my post.
It’s not obliquity alone, but modulated by precession-eccentricity.
The whole point of my post was that precession and 65N summer insolation modulate the response of the glacial oscillator to obliquity. I’ll say it for the 4th time. With the 6,500 year lag, every single temperature peak correlates with an obliquity peak. And why are some tall and some short, some almost nonexistent ? The tall ones which are called interglacials were the ones coinciding with the eccentricity / 65N max summer insolation / precession peaks. Resonance, if you like.
dscott is right, obliquity is obviously the prime Milankovich forcer of the interglacials. Those who persist in opposing Milankovich pacing of glacial cycles do so for religious reasons and employ the tactics of creationists in their argument, like the “Gish gallop” – an apparently impressive plethora of irrelevant arguments, and inflating the importance of non-zero error in experimental measurements.
Precession modulating obliquity with. 6500 year lag, explains perfectly all the glacial-interglacial oscillation of the last million years and probably further back as well.
ptolemy2:
I am in a quandry. Your analysis appears to be “right on”, but episodes of volcanic cooling, (and warming when they cease) are inescapable,
It seems far-fetched that they would be in sync with your alignments, but perhaps they are.
What is your view?
This was actually Javier’s analysis – obliquity and the 6,500 year lag – not mine.
Volcanism is clearly influenced by the glacial – interglacial cycle, as shown by papers such as this (if one filters out the CO2 worship):
http://www.cam.ac.uk/research/news/increase-in-volcanic-eruptions-at-the-end-of-the-ice-age-caused-by-melting-ice-caps-and-glacial
For instance the melting of glacial ice caps releases pressure on underlying rock, causing an increase in volcanoes 🌋. Glacial erosion also appears to play a role in this.
The authors of the link cannot be right. More volcanism will cause cooling due to sulfurous emissions, negating any warming trend.
And CO2 from volcanic eruptions is a fiction–none has ever been observed from any of the major eruptions during historical times, just cooling.
Sun’s graviatational foce is 180 times the moon, and varies 30% during a year at maximum Milanovitch eccentricity, when the sudden warming to interglacials occurs. I have already written what this could , and does on other planets and Moons we recently learnt about, Check out Io and what’s under the Venusian clouds due to no plate etctonocs, probably. If toides matter, they wil also be part of the picture of substantial variatio durinf Milankovitch extremes.