What modulates our Sun? The majority of science work on the principle that the Sun is self modulating and each solar cycle is a product of a random number generator. There are others that suspect the Sun is modulated by the planets with a special emphasis on Uranus & Neptune. Thanks to Carl Smith who has recently left us we have new knowledge that significantly adds to Jose, Landscheidt & Charvàtovà's work.

Geoff Sharp

Is the World Ready for Another Ice Age?

Little Ice Age conditions are sweeping across most of the northern hemisphere creating travel chaos, financial damage and, unfortunately, many deaths in the process. I predicted this back in July 2010 in my " A Massive Winter Heading for the Northern Hemisphere?" article that has come home to roost. An excerpt  "I predict the extra boost from my predicted solar grand minimum along with the current oceanic conditions the next northern winter will experience conditions similar to the Little Ice Age (1250-1850)."

The conditions are perfect at present for continued cold, the oceans are cold with the important atmospheric oscillations forcing cold arctic air further south than usual. The negative AO and NAO are producing blocking high pressure cells that bend the jet stream which allows the southern movement of arctic air. At present there is an unusual permanent high pressure cell over Greenland.  I think this pattern should prevail over the next 20 to 30 years and replaces the positive pattern of the last 30 years. The global warming models have suggested that man-made CO2 will keep the AO and NAO in positive wrong have they been?

Many are asking what causes the global ocean and atmospheric oscillations to follow these heating and cooling trends. The Pacific Decadal Oscillation (PDO) is a large player that has a 60 year cycle, this follows the solar velocity oscillations as the sun orbits the centre of the solar system as described by Scafetta. The NAO works very closely with the PDO but is possibly governed by changes in the height of the atmosphere as a result of the reduced EUV that is a product of a quiet Sun. NASA has reported that the height of the Thermosphere is at the lowest point since records began; EUV is a controller of atmospheric height. We are told that the TSI or total heat output of the Sun only varies by 0.1 percent over a typical solar cycle. But we are now learning that the Sun has other ways of affecting climate that the models have not allowed for. EUV is capable of a 16% (correction: 30-100% depending on wave length) modulation over the cycle and, at present, is refusing to ramp up. This current minimum sees the EUV level 15% lower than the previous minimum which, if correct, dispels the theory of a solar base floor.

With solar output being so crucial to climate, where are we heading in the next hundred years?

Right now I think we are heading into a solar grand minimum that will last 2 cycles producing a very different world compared to what we have experienced over the last 30 years. After that a brief warming will occur before slipping into a familiar pattern that started in the early 1900's, which is more cooling gradually warming over several decades. The Sun is controlled by its angular momentum which is in turn controlled by the outer planets...My published paper has all the details for those wishing to dig deeper.

Click on the pic for a larger view.

But is there more? There are two types of global cooling - one is solar output modulation as discussed, but lets look at the other. Over the past several million years the planet has spent around 80% of its time under ice. There is a regular pattern as discovered in the Vostok ice cores that show us a roughly 100,000 year cycle of ice ages. Mankind for the past 11,000 years has enjoyed the Holocene which is an interglacial or warm period that will soon come to an end. The outer planets over long periods influence the shape of the earth's orbit via gravitation perturbations. This has the effect of changing the way heat is received from the Sun which leads to a gradual build up of snow/ice that does not melt during summer in the northern hemisphere. But looking at the ice core records we can see a fairly abrupt change in temperature that suggests there is another factor in play governing what tips us into the ice age plunge. It is very possible that a solar grand minimum that is in position at the right time could assist the natural orbital changes as outlined via the Milankovitch Cycles. A kick start forced on by 30 years of negative PDO, AO and NAO might be all that is needed to push us over the edge...we are well overdue, but of course this is highly speculative.

We are now two years into solar cycle 24 and today we are heading into our 8th consecutive spotless day as counted by the Layman's Count.  This cycle is currently undercutting the first cycle of the Dalton Minimum. Solar F10.7 flux has struggled to get over 80 all year and currently this month is likely to show a further decline. If you would like to follow the daily progress of solar cycle 24 be sure to check out the Layman's page and I also encourage any questions and discussions relating to this article, simply register as a user and fire away.


Great post, although I think

Great post, although I think it is unlikely that we are on the brink of entering an Ice Age just yet. Perhaps a more prolonged Grand Minimum, such as the Maunder/Sporer, or a set of prolonged/severe Grand Minima such as those between 1300 and 1850 would provide the right conditions for the right amount of time to push us over the edge. But if we're heading towards a few centuries of higher solar activity after this short but sharp 20-30 year Grand Minimum, I don't think it is very likely. Also, no two interglacials are the same, the Holocene seems to be very different to the previous one, right from the start, as we can clearly see from the graph, and Termination V circa 400,000 years BP lasted 25,000 years. The various Milankovitch cycles must be fairly complex in such a case. Here is a link to a website which says that only the Earth's precession is in glacial mode and that axial tilt and eccentricity are not:  Also, aren't the planets' orbits constantly changing anyway, so that the Gas Giants perturb the Earth's orbit differently now to in the past?

N.B: This is my first White Christmas!

Yes, I agree with your

Yes, I agree with your comments, but the past has shown us that an ice age happens very quickly. The changes to orbit shape, axis tilt and precession happen very slowly, but perhaps they have to be all in the right place to trigger this decline. I would like to explore this area more scientifically but I am unsure if the relevant data is available going back 500,000 years. You are also right about the different planetary positions each time that could change the timing of this interglacial period. We only have a small time frame of data to work with and this area is in its infancy with many unknowns. I think there needs to be another force in place to push across the background Milankovich forces that happen slowly, whether it happens now or way in the future is subject to understanding when the window of opportunity comes in to play.

Which grand minimum will trigger the decline?. This area of the the post is highly speculative.(comment added to article)

Noel makes a good point, I

Noel makes a good point, I think this minimum will be short, but the current AM pattern is almost the same as the main pattern of the Maunder as Gerry has shown us. A short but perhaps deep minimum will have consequences, the northern hemisphere will be a test over their winter.


On the topic of Ice Ages,

On the topic of Ice Ages, here is some interesting work by Richard A. Muller entitled "Glacial cycles and orbital inclination" which states that orbital eccentricity cannot account for the temperature swings because the change in insolation is so small. Instead, he proposes that a 100,000 year cycle of orbital inclination drives the Ice Ages, with some very strong input from the 41,000 year obliquity cycle and an orbital precession cycle.

He claims that the orbital inclination theory fits better with well-known climate cycles. He also suggests a possible mechanism to how inclination would affect climate, since it would have a very negligible effect on insolation. He says that increased extraterrestrial accretion from asteriods and space dust cools the Earth which sends it into an Ice Age. (Perhaps this could cool the Earth by directly reflecting sunlight, like volcanic ash or providing more nuclei for cloud formation, reflecting more sunlight away, resulting in more snow/ice and a positive albedo feedback). He claims that the when the Earth's orbital inclination is low, it is closer to/within this this unconfirmed belt of material.

Here are two links to this work, I think it is well worth reading/looking into; since an Ice Age is one of the worst things that could happen to humanity and because Ice Ages are still relatively poorly understood:

Hey, great piece. I only

Hey, great piece. I only have problems with the general lack of precision in defining what an ice age is. Is it the last 5 cycles discovered by Milankovitch and I believe will persist into a sixth cycle where we are already 2000 years into a glaciation as evidenced by Antarctica? Is it the few million years of the Quatenary Period where we have had these 'glaciation' / 'interglacial' cycles (modified Milankovitch)? After much reading I personally think that the 'Jose Cycle' is only significant to be noticed at the margins. Outside the relative heat of the Holocene Optimum and the depths of the previous and present glaciation, I believe the barycenter variation is noticable and therefore we get Medieval Warm Periods and Little Ice Ages. I think in a couple thousand more years when the 'glaciation' in this Milankovitch Cycle matures and we get a Heinrich Event (drivers unknown), we can all move to the greening Sahara ;)


REPLY: Hi, I was assuming the Milankovitch Cycle, the interesting aspect for me is that the sudden cooling and warming shown on the ice core record suggests a trigger point, which nobody seems to understand the timing of.

One attempt to straighten out

One attempt to straighten out the terminology uses the term Ice Epoch to cover periods with polar icecaps that periodically advance onto the continents (ice ages) and then briefly retreat (interglacial).

There have been at least seven ice epochs. They have all occurred when the configuration of the continents block a circum-global current, and in all but one there was a continent on the south pole. The switch between very warm (22C avg temp- think dinosaurs and coal forming swamps) and ice epoch (as now, 12C avg temp) seems to be controlled by continental drift.

Inside the Ice Epochs, the very regular cycles point to something much less random. Milankovich cycles fit for the 100K year Ice ages, but it's the climate fluctuations during interglacials, and what tips an interglacial into an ice age that we don't really understand. Thank you for this site, I think the close monitoring of the solar conditions, and coming to an understanding of causes is desperately needed.  

Thanks Pam, the subject of

Thanks Pam, the subject of changing ocean currents as a trigger point for glacial periods is one to watch I think. If the Gulf Stream cooled, changed direction or stopped this alone could be enough to start the decline if associated with some of the Milankovitch components in the right place. The Gulf Stream looks very cool on the world SST graph recently.

Yeah, my inner scientist is

Yeah, my inner scientist is all excited that we seem to be on the path to learning so much about the onset of either a "Little Ice Age" cycle or a full blown Ice Age. My outer-self hopes we're just looking at a short cooling cycle.  I'm getting more pessimistic with every month the minima continues.

Pam and Geoff, I guess I

Pam and Geoff, I guess I should clarify my rambling above. Pam mentions epochs ... not being a paleo-climate scientist I revel in information like this. Thanx.

On the other hand I think Milankovitch is alive and well (10,000 year interglacial) and we have been in a 'ice age' or glaciation since the time of Christ. I have found nothing to refute this conclusion and our ignorance of the state of Antarctica over the past 20k years is frustrating. What I'd like to see is some causation for Heinrich Events. After all, homo sapiens were living comfortably on Russia's Southern Steppe during the last 'ice age' until one of those happened and suddenly they were living off dying herds of Mammoths for a couple generations in a deep freeze.

I think these events are what we should fear and what we least understand. I can take the Dalton (Landscheidt/Smith/Eddy) Minimum we are living in well enough. Doesn't really mean much on the Northern Plains except more moisture ... you can't make the winters much more brutal ... even with the tree line dropping a few feet in the Rockies like it did in the Little Ice Age. We got sophisticated heat in our homes, 90 day wheat for our bread, 60 day corn for the garden, AWD vehicles ... a few degrees means more in the midwest ;)

That doesn't mean I don't check the sun spots every day and laugh at Hathaway ...

Thanks Geoff for this topic.

Thanks Geoff for this topic. Your worry that the current sun cycle might be the trigger that ends the Holocene has been on my mind as well. There has been some research papers that I found interesting. One paper suggests that ocean tide level records miss capturing past intermediate interglacial cycles that follow eccentricity as these cycles trade off southern ice for northern ice and thereby show little ocean level change expected for interglacials. Another paper points out that after looking at 20 or so sedimentary sites, that the ocean currents fail to reliably follow glaciation changes, and thus contradict a research paper that looked at only one unrepresentative sedimentary location (bad luck). So ocean currents don't seem to be a reliable common factor.

Another point made by a poster is that although triggers for an interglacial start vary, the ending of an interglacial consistently occurs at obliquity of 23.4 down swing, which is where we are now. It may be that the LIA was too soon for a glaciation event trigger. Also, the interglacial at 400kyr may look long, but it had a large drop at 12kyr into it and did not recover. Moreover, I wonder at the resolution of the records and interpretations. The higher resolution graphs I have seen don't make the 400kyr interglacial look so impressive, looks like just a 12kyr, not 25kyr. Just saying.

A previous thread poster pointed out major positive agricultural improvements and they are heartening, but China this summer has had major grain crop failure and will be the world's big importer this next year. Furthermore, Canada is a major wheat producer and is vulnerable to marginal changes. I pray for a major fusion power breakthough soon, which is possible (not ITER though) and would be vital for new economic irrigation that facilitates opening of currently unusable land for crops.

Like you said though, no one knows. We will just have to watch and see. Thanks.

Mike VanWinkle

First congratulations Geoff

First congratulations Geoff on getting the excellent paper published.!

in relation to comments above, the extended 400KY interglacial commonly quoted I believe results from the phase relationship between eccentricity and obliquity at the time which does not apply now. This shows up in the wikipedia picture from Rhodes and in other charts showing the net orbital insolatation at Lat.65N.midsummer. A dent in the 400KY peak caused by the sum of eccentricity and obliquity  has the effect of flattening and extending the cycle at that time.

I think there is a strong possiblity of a glacial transition this time. Net orbital insolation is now down near the level at which all the other transitions ocurred.

A question relating to the forecast SSC : Geoff have you examined the case when one or more of the four planets are at perihelion when the conjunctions and oppositions occur? That might lead to a more intense jerk on the Sun and explain some of the longer term sudden cold events such as the Younger Dryas. i think also the 8200Y event.



Thanks for your support

Thanks for your support Peter, the outcomes for the start of the next ice age are perplexing, I am not sure anyone quite has a handle on it.

In relation to the perihelion of the major planets affecting solar cycles I think the small distance difference would matter little. If we are following the Angular Momentum Perturbation theory the position of Saturn is the key to how much the solar orbit is affected. This position would highly override any small variations in planet orbit size.

Many thanks go to Carl's brother Dave for providing the Domain, Server and Software.