Albedo regulation of Ice Ages,
                 with no CO2 feedbacks.
                                by Ralph Ellis      
This is a very simple and apparently novel proposal for the initiation and modulation of Ice Ages and Interglacials, that explains all the many peculiarities and periodicities of recent Ice Age cycles. And it is a theory without unwarranted preconceptions. In Climate Sensitivity Estimated From Earth's Climate History, by James Hansen and Makiko Sato,*2 they declare a priori in the first sentence of their introduction:

The largest climate forcing is the human made increase of atmospheric greenhouse gasses, especially CO2, from the burning of fossil fuels.

While that may be an essential statement to assure further grants, it is an unwarranted and incorrect assumption that is directly contradicted by the paper itself. And if the very first sentence in a paper is wrong, there is little hope for the following study.  

In great contrast, the proposal for consideration in this paper is that the recent Ice Ages and Interglacials are initiated by precessional Milankovitch cycles, and enhanced almost exclusively by albedo feedbacks, plus a special 'secret' ingredient. The main conclusions of this research paper are that:

a.   Ice Ages and Interglacials are initiated by precessional Milankovitch cycles.
b.  An incorrect orbital cycle has been assumed, as the initiator for Interglacials.
c.   Ice Ages and Interglacials are enhanced by albedo feedbacks, not CO2. 
d.  Milankovitch forcing has been erroneously reduced in climate research.
e.  Albedo feedbacks have been erroneously reduced in climate research.
f.   CO2 feedbacks have been erroneously exaggerated in climate research.
g.  CO2 feedbacks are unnecessary, to explain Ice Age modulation.
h.  An extra 'secret' ingredient is involved in Interglacial initiation.

While the following arguments may be very simple, they do manage to explain almost every aspect of recent Ice Age cycles, and also some of the lesser known ones. And if this hypothesis is true, then it is likely that CO2 plays a greatly reduced role in all modern climate feedbacks, not just Ice Age feedbacks. And this would mean that all the IPCC predictions about the present climate are likewise false. 
Abbreviations used:
NH    =  northern hemisphere
SH     =  southern hemisphere
GY    =  Great Year (a precessional 'year')

Ice Age initiation (forcing):

In the standard Ice Age temperature graph in fig 1, we see that Interglacials are regular events that must therefore be triggered by some very stable, long-term regular cycle. This is not the chaotic initiation via a random weather event, but the regular rhythm of a celestial cycle. 

It is often said that recent Interglacials have a 100 k year cycle, and must therefore be linked with the 100 k year eccentricity of the  Earth's obit. Strangely, for such a simple observation, this oft-quoted assertion is completely wrong. Even looking at the Interglacials in fig 1 will demonstrate this, because the last two Interglacials are about 110k years apart, while previous Interglacials are displaced by about 90 k years. So is this observation significant in any way?

Surprisingly, it is pivotal. Because how can we understand the mechanism behind Interglacial initiation, if we do not know what the underlying cycle is? Many researchers have been led astray because a mathematical frequency analysis of the data can combine two closely spaced cycles and erroneously points towards single a 100 k year cycle. So there are many analyses, like the 1997 paper by Muller and McDonald entitled Origin of the 100 kyr Glacial Cycle: eccentricity or orbital inclination *1 that misidentify the astronomical cycle. In fact, the rather humorous answer to the title of their paper is: neither!  This is where observation and experience can triumph over the raw and untamed power of fourier transform mathematics, because the true Ice Age cycle is not a single 100 k fluctuation at all, but multiples of smaller 21,700 year oscillations. 

And so the true answer to this cornerstone of Ice Age climatology, is that the correct astronomical metronome for recent Ice Age initiation is the Earth's axial precession, not its orbital eccentricity or axial inclination. The precession of the equinox has a 25,700 year cycle, and it was known to the ancient Egyptians and Greeks as the Great Year. And its comparison to a solar year is perfectly valid, because the Great Year combines with orbital eccentricity to produce warm and cool seasons in each hemisphere just like a normal year  -  Great Seasons that are 5,420 years long.  (The Great Seasons are shorter, because of apsidal precession. So the Seasonal Great Year is only 21,700 years long, instead of 25,700 years.) And since a solar year has twelve months, the Great Year was also traditionally sub-divided into twelve Great Months of 2,140 years each (excluding apsidal precession). But in practice each of the Great Months in antiquity were of different lengths, because the astrological constellations that defined them are all of different sizes. So the knowledge and study of the precession of the equinox is of great antiquity. 

(Note that the precessional Great Year requires some orbitial eccentricity, before its seasons will differ. This is why some Great Seasons are stronger than others. See the red line in fig 9, where larger oscillations equal stronger seasons.) 

The Seasonal Great Year of 21,700 years in length is the reason for the variability in Interglacial spacings. If an Ice Age spans four precessionary cycles or Great Years, it will have a total cycle length of 87 k years, but if it spans 5 Great Years it will have a total cycle length of 109 k years. And this is exactly what we see in the historic climate record, as fig 1 demonstrates. However, climate scientists will dismiss this suggestion as being impossible, because a mechanism is then required whereby Ice Ages can span four or five Great Years (precessionary cycles) before producing another Interglacial. Why would any cyclical system miss out a number of intermediate cycles before responding? This is a good question and it will be fully explained later in this paper through the action of a special 'secret' ingredient. 

 

Fig 1.
Global temperature vs CO2 over 450,000 years from the Vostok ice core.  Ice Ages are at the bottom of the graph, Interglacials at the top. Note that CO2 concentrations follow global temperatures, rather than lead them. So CO2 is a follower, rather than an initiator and driver. Source: NCDC, NOAA. http://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core

 
However, there should be no doubt about the initiating trigger for Interglacial periods, because the clear evidence for this is given to us in fig 2. The blue line in this graph is the variation in insolation in northern latitudes, caused by Milankovitch cycle Great Years (GY). Thus all the upper peaks in this Milankovitch blue line are 21,700 years apart, and represent the NH Great Year summer season (a summer season that is 5,420 years long). And it is quite apparent that both of the major Interglacial warmings and all of the minor warmings depicted here, follow the Great Year's NH spring and summer seasons. Note that temperatures do not follow the SH GY summer, which are represented by the troughs in this blue line, but only follow the NH GY summer. The difference being that the NH contains the great landmasses, and so we know that land is more important than ocean in Interglacial initiation and propagation.

So the major recent Ice Ages are not modulated by orbital eccentricity, as is often assumed, and nor are they regulated by obliquity-inclination. Instead, they are actually regulated by the precession of the equinox and its resulting Great Year seasons. So just as the standard solar spring and summer seasons will chase away the winter snows in the NH, so too will the Great Year's spring and summer melt the Ice Age ice sheets in the NH  --  sometimes. 

This is why there are some shorter Ice Age periods of about 90 k years and longer ones of 110, k years, because they are responding to an underlying 21,700 year cycle. This does mean we need to explain the missing cycles, like the very obvious one 170 k years ago which did not produce a temperature response at all, but the reason for the selective response to NH Great Year summer forcing will become apparent later. 

But the important thing we know thus far, is that Interglacials are regulated by the Great Year, and only by the rising insolation during the Great Year's summer season in the NH. Note that no Interglacials are ever triggered by increasing insolation in the SH. The SH graph would be the inverse of the cycle in fig 2, so if there had been a SH warming that resulted in an Interglacial, the pink temperature line would coincide with a trough in the blue line in fig 2. And this is again a pivotal observation. So the requirements thus far for an Interglacial period are:

a.  Increased insolation linked to the 22.7 k year Great Year.
b.  Only increased NH insolation will produce an effect.
     (ie: during the NH Great Spring and Great Summer seasons.)
c.  The NH landmasses are an important factor, for some reason.
d.  Not all NH Great Summers produce a temperature response.



Fig 2.
Changes in insolation in high northern latitudes during the last 11 Great Years (Milankovitch Cycles). Each Great Year's NH summer season is shown by the peaks in the blue graph-line, and the Great Year's NH winter is represented by the trough. The pink line is the resulting worldwide surface temperature. 
Source: http://www.climatedata.info/forcing/milankovitch-cycles

Science papers will undermine the role of Great Year Milankovitch forcing by saying that the total forcing over the whole globe and the whole Great Year  is very small, averaging just 2 wm2. And so this very small forcing needs assistance in the form of a very strong feedback - CO2. So in the minds of both scientists and the media, CO2 becomes the vital feedback ingredient.

However, although there are feedbacks involved in Interglacial warming, the dilution of Great Year summer forcing all over the globe is totally fallacious. We have already established that Interglacials are only a NH forcing event, and so spreading the effect of Great Year forcing across the globe is a totally false and unwarranted methodology. When it comes to melting the annual winter snows in the NH, it is not the temperature in Australia that matters. NH winter snow melt is initiated and sustained by local temperatures in the NH, and more pertinently by local temperatures in the high northern latitudes. So why would ice-sheet melt during the precessional Great Spring and Great Summer be any different? 

We shall see further evidence later demonstrating that Interglacial warming is actually a high latitude phenomena, caused by increased insolation on the northern ice sheets themselves. And so the true regional increase in insolation during the NH's Great Year summer season is much the same as in fig 2. The present Interglacial warming had 50 wm2 of extra insolation-forcing, while the previous Interglacial had an even larger 90 wm2 of extra insolation-forcing, in the high northern latitudes. So while a Great Year insolation-forcing of just 2 wm2 smeared over the whole globe does not appear very great, the regional insolation-forcing on the northern ice sheets themselves can be up to 90 wm2, and that is a highly significant increase in solar energy.

But this increased Great Year (GY) forcing is obviously not the full story, because some NH GY summer seasons are completely ignored by the global surface temperature. The GY summer of 170 k years ago is a good case in point, where 80 wm2 of extra regional insolation in the NH produced no temperature response whatsoever. Why was that? What can produce such a different response between the GY summer 170 k years ago and the GY summer 135 k years ago, which produced a full-blown Interglacial warming? The answer is an additional 'secret ingredient' that will be explained in more detail later.
  
Ice Age enhancement (feedbacks):
The oft-quoted primary feedback involved in Interglacial formation and enhancement is the mighty CO2 molecule, which has seemingly miraculous properties. It can influence anything from surface temperatures, to floods, to diseases, to animal behavior, and life expectancy. And so the miracle molecule just has to be involved in the Interglacial warming process too. But it is not, and we can see some evidence for this in fig 1, where the Ice Ages appear to have well defined and delineated maximum and minimum temperatures, no matter how warm the GY summer was or how cold the GY winter was. So there is obviously another factor involved here, that modulates and regulates surface temperatures during the GY summer and winter, but what is it? 

The miracle molecule, CO2, will produce a positive feedback effect, as we all know. But the effect is produces is not significant. Fig 3  shows that between the Ice Age concentration of 180 ppm and the Interglacial concentration of 300 ppm, the extra forcing energy provided by CO2 is only 4 wm2:
    
    Age                  CO2                Insolation
    Interglacial     300 ppm        258 wm2
    Ice Age            180 ppm        254 wm2
    Difference       120 ppm        004 wm2

So over the course of an Interglacial warming period CO2 feedback-forcing averages about 4 wm2, which represents roughly a doubling of CO2  (the oft-quoted 'doubling of CO2' warming figure).  But this 4 wm2 is the total contribution of CO2 over the entire Interglacial period, and if we assume an Interglacial warming period of 5,000 years, this results in 0.008 wm2 per decade of extra insolation and extra warming. And this is about half the energy required to power a bee in flight. One has to wonder how 0.008 wm2 over the course of a decade, is going to assist in warming a frozen planet into an Interglacial period. 
        
Fig 3.
The 'feedback-forcing' ability of CO2.  Note that the effects of CO2 are greatest in the first 100 ppm, and then the graph flattens out.  So the effect of rising from 400 ppm to 500 ppm of CO2 is very small indeed. 

The underestimated feedback:
According to current literature a doubling of CO2 is assumed to be the equivalent of 4 wm2, and this will give a 1.5ºc change in global temperature (with CO2 alone doing the feedback). In which case, the 0.008 wm2 increase in CO2 forcing calculated above will give a 0.003ºc warming per decade. This paltry increase in energy is simply too insignificant to deliver a decisive feedback that will instantly force the world into an Interglacial. During the last Interglacial warming the world was warming at 1ºc per 1,000 years, and 0.008 wm2 per decade is simply not going to cut the ice (sic), and so there are obviously some missing feedbacks here. 

To overcome this deficiency it is claimed that CO2 is further assisted by water vapour and methane and also by albedo changes, to create a much more substantial change in world temperature. These extra components are thought to treble CO2's contribution, resulting in a 4.5ºc change in temperature per extra 4 wm2 (a doubling in CO2). This translates into 0.009ºc warming per decade over the entire Interglacial warming period of 5,000 years, and is about the temperature increase observed during the Interglacial warming period. 

    CO2+H2O positive feedback:
    Great Year increased insolation 
     = More CO2+H2O = More greenhouse warming == More CO2+H2O = More greenhouse warming.

    Albedo positive feedback:
    Great Year increased insolation 
    = Less ice = Less albedo = More warming == Less ice = Less albedo = More warming.


Do note that ice-sheet albedo has largely disappeared from these feedback calculations for the modern era, because the ice sheets have largely disappeared. And so the Earth System Sensitivity (ESS) calculation of 4.5ºc for a doubling of CO2 (with ice sheets), has now become the Equilibrium Climate Sensitivity (ECS) value of just 3ºc for a doubling of CO2 (without ice sheets). (A doubling of CO2 represents about 4 wm2.) 

But there is a problem here, because the large role played by CO2 feedbacks in the ESS and ECS forcing values has been calculated primarily from Ice Age temperature data. (Laboratory experiments have given an enormous variation in results, indicating that they cannot be taken seriously.)  But are these Ice Age feedback calculations correct? If albedo takes on a much greater role in Interglacial feedbacks, as will be demonstrated later, then the role of CO2 must be diminished to compensate.

For instance, the ESS value assumes about a 33% feedback contribution each, for CO2, H20, and albedo (Hansen and Sato, fig 5  *2). However, if the effect of albedo feedbacks doubled to 66% of the total, then CO2 and H20 would be reduced to providing just 17% each. More importantly, this suggestion would also have an impact on feedback calculations for the modern ice-free climate: 

       ESS  (with ice-sheet albedo):
       Classical sensitivity     4 wm2   =   4.5ºc rise   incl   1.5ºc     from CO2.   (33% of  4.5ºc)
       Revised sensitivity      4 wm2    =  4.5ºc rise   incl   0.75 ºc  from CO2.   (17% of  4.5ºc)

       ECS  (without ice-sheet albedo):
       Classical sensitivity     4 wm2   =   3.0ºc rise   incl  1.5ºc     from CO2.   (50% of  3.0ºc)
       Revised sensitivity      4 wm2    =  1.5ºc rise   incl  0.75ºc   from CO2.   (50% of  1.5ºc)


So if we incorporate a much larger effect from albedo feedbacks, when calculating Ice Age climate sensitivity, then the role of the CO2 feedback has to be diminished to compensate - in this case reducing from 1.5ºc to just 0.75ºc for a doubling of CO2. Furthermore, the role of CO2 in the modern era will also be diminished, and so the all-important total climate sensitivity reduces from 3ºc to 1.5ºc for a doubling of CO2. In which case, CO2 would not be such a powerful modulator of the climate, and the threat of a runaway warming effect from increasing man-made CO2 emissions is likewise diminished. And we shall see later that the role of ice-sheet albedo may be much greater than the 66% assumed in this calculation, which would result in an even smaller role for CO2 in the modern climate system.

This reduced role for CO2 in feedbacks (a reduced climate sensitivity) would explain the closely delineated temperatures during Interglacials. If CO2 really did represent a very strong positive feedback system, and the primary regulator for Earth temperature, then the huge rise in CO2 concentrations during the Interglacial warming could well produce the dreaded 'tipping point' and 'runaway greenhouse effect' that the BBC and CNN try to scare us with every other day. The CO2 feedback would be so strong, that the Earth would just continue warming.  

But increasing CO2 concentrations do not cause runaway temperatures at all. As can be seen in fig 1, maximum CO2 concentrations always result in global temperatures stabilising at about the same temperature, followed by reducing temperatures as the Great Year in the NH turns to autumn and then winter. And this is despite CO2 still having plenty of warming potential left in it. CO2 can continue giving a positive feedback effect all they way up to 1,000 ppm. And yet it does not. The Interglacial CO2 concentration always stops at about 300 ppm, and the temperature always stops at about our current world temperature. And the same maximum world temperature has been reached in each Interglacial and each warming period for the last 2.5 million years, as fig 4 demonstrates. 

However, while CO2 cannot explain this Interglacial temperature limit, albedo feedbacks can. An albedo feedback driven by changes in polar ice will always result in a maximum temperature limit, which is reached when the majority of the ice has gone and there are no further significant changes in ice-albedo. And from this observation alone, we can rightly assume that the alarming reputation of CO2 as the primary regulator of world temperature has been grossly exaggerated. And that exaggeration has resulted from a complete misunderstanding about the causes and processes that trigger and assist an Interglacial warming event.  

Fig 4.
World temperatures over the last 5.5 million years. Note that our current world temperature has been the same maximum value for the last 2.5 million years. A very consistent maximum temperature indeed.

Feedback strength:

We have already seen that CO2 on its own produces a very weak feedback effect, averaging a 1.5 ºc warming over the entire Interglacial warming period (during which CO2 concentrations approximately double). To overcome this deficiency it is claimed that water vapour feedbacks will assist CO2, to create a more meaningful forcing component.  Water vapour, so it is said, will double the effect caused by CO2 resulting in 3.0ºc of warming over the course of the entire Interglacial warming. (And albedo, so it is claimed, will add another 1.5ºc making a total of 4.5ºc.)  But the assertion that water vapor assists CO2 feedbacks is probably incorrect.

Several climate realists have claimed, with good evidence and reasoning, that while water vapour itself may be a positive feedback, the clouds it creates represent an even stronger negative feedback. In other words, the combination of water vapour plus clouds will combine to form a negative feedback that resists temperature variations instead of enhancing them. Clouds increase the Earth's albedo just as strongly as snow and ice does, as can be seen in fig 5, and so water vapour plus clouds actually results in a stabilising negative feedback upon surface temperatures.

    Cloud negative feedback:
    Warming Earth = More clouds = More albedo = Cooler Earth

    Cloud reverse negative feedback:
    Cooling Earth = Less clouds = Less albedo = Warmer Earth 

So water vapour plus clouds will regulate temperature like a thermostat, and keep the Earth temperature stable within tightly set bounds. And if this is so, then almost everything that the IPCC has claimed over the last 30 years, is incorrect. An essential component of the CO2 warming theory and scare story, is that CO2 will be assisted by H2O to create a more powerful feedback. And if H2O is not assisting CO2, but opposing it instead, then the entire CO2 Global Warming theory lies dead in the water.

This cloud thermostat-regulation theory has been expounded by Willis Eschenbach, amongst many others, and it is simple, logical, and of serious merit. And if proven correct, this theory alone destroys the CO2 Global Warming industry, let alone the additional effects of albedo being explored in this paper.

http://wattsupwiththat.com/2015/06/04/an-inherently-stable-system
http://wattsupwiththat.com/2015/06/08/the-daily-albedo-cycle
http://wattsupwiththat.com/2015/08/18/cooling-and-warming-clouds-and-thunderstorms
So if CO2 and H2O appear incapable of assisting and enhancing Interglacial warming events, then what about albedo? Surprisingly, the albedo feedback is very strong, as can be seen in fig 5.  Insolation at 65N in the summer averages 460 wm2, and if we delete the cloud albedo then about 380 wm2 of that insolation reaches the ground.  But if the land is covered by snow and ice the albedo reflections can be as high as 85%. And so up to 320 wm2 of the Sun's insolation is being reflected away and not assisting in warming the northern latitudes at all. This is a maximum figure for albedo, so let us take 60% as the Ice Age average in higher latitudes, which would mean that about 230 wm2 of the Sun's energy is being reflected away and only 150 wm2 is being absorbed by the ground. 

As the snow and ice melts during an Interglacial period, the albedo of the land reduces to about 10%, or about 40 wm2 reflection. So in comparison to the high albedo Ice Age era, the ice-free Interglacial land is absorbing an extra 190 wm2.  You see the great difference here.

     CO2 feedback-forcing increase, up to    4 wm2  (worldwide, spread over 5,000 years)
     Albedo feedback increase, up to         190 wm2  (regionally, each and every year)

However, in great contrast to this simple comparison, mainstream science smears this significant albedo forcing out across the entire globe, just as it did with the Great Year's summer insolation increase. For instance, in Climate Sensitivity Estimated From Earth's Climate History, James Hansen and Makiko Sato manage to reduce albedo forcing down to 3 or 4 wm2 (see their fig 6). *2  They do so by directly equating albedo with sea levels, and therefore with ice extent:

Climate forcing due to albedo change is a function mainly of sea level, which implicitly defines ice sheet size. 

But this calculation implicitly spreads albedo feedbacks across the whole globe. But this is a completely erroneous procedure. In the everyday world, the annual melting of snow and ice in Canada is caused by regional insolation and temperature increases in North America, and not by the ambient temperature in Argentina. Likewise, albedo warming of the NH ice sheets during an Ice Age is a local phenomena in the NH, as fig 2 clearly demonstrates. Interglacial warming events are never triggered by increased SH insolation during the SH Great Year summer, so why spread albedo feedback-forcing out across the entire globe and make it look weak and ineffective? And yet having done this, Hansen and Sato also say in the same paper:

As quantified below, the magnitude of these orbital climate oscillations is determined by CO2 and surface albedo changes, with both mechanisms operating as powerful feedbacks … The surface albedo feedback was largely absent in the early Cenozoic, when the planet was too warm for large ice sheets to exist. But by the Pleistocene, when the planet had become cold enough for a large ice sheet to exist in North America, the orbital climate oscillations became huge.

According to Hansen and Sato, CO2 and albedo were equally powerful feedbacks during Ice Ages, as their fig 5c clearly illustrates. However, it was only when ice-sheet albedo feedbacks existed that 'climate oscillations became huge'. But this quite valid observation is in complete contradiction to the rest of their paper. You cannot have equally powerful feedbacks, and simultaneously claim that one completely dominates the other. If CO2 is as powerful as albedo then why did the Cenozoic era only have small climate oscillations? There was plenty of CO2 in the atmosphere during the Cenozoic era to act as a feedback, and yet it did not for some reason. And why did climate oscillations only become huge when 'the planet had become cold enough for large ice sheets to exist' ?  How did albedo so comprehensively overpower CO2, when they are supposed to be equally powerful feedbacks? Hansen and Sato are not exactly making sense. How a paper that is littered with such fundamental contradictions passes peer-review, is a bit of a mystery.

The answer to this question and many other Ice Age problems, is that albedo is more of a local and regional feedback than a worldwide feedback, just as the Great Year's summer insolation effect is also local and regional. And albedo's feedback-forcings are much stronger when calculated locally, than when erroneously smeared out across the globe. From my own empirical observations the melting of dirty ice sheets is not really a function of ambient temperature, it is more a function of direct insolation on dirty ice, as I found out when I did some research on the Baltoro glacier in the Himalaya (see fig 6). And the Ice Age ice sheets did became dirty, as we shall see later, although probably not to the degree that the Baltoro glacier does. 

In which case, if the increased albedo feedback-forcing is a local phenomena with sunlight warming the (dirty) ice sheets directly, the increased absorption during the Great Year summer can be as much as 190 wm2. And this huge extra feedback absorption is not all spread out across the entire 5,000-year Interglacial warming period, as the CO2 feedback will be. A patch of dirty ice will greatly effect albedo and insolation absorption levels from day one. And if the dirt stays on the surface, just as the rocks and dirt stay on the surface of the Baltoro glacier, then the albedo-absorption will be greatly increased for each and every solar year during the entire Interglacial warming period. So if we take a modest 20% decrease in the total albedo on the ice sheets, the true feedback comparison may be more like:
     CO2 feedback-forcing increase, up to     0.0008 wm2  (worldwide per year)
     Albedo feedback increase, up to           80 wm2           (regionally every year)
   

So what is going to have the greatest effect on ice sheets and glaciers  -  the mighty albedo or the puny CO2?  Quite clearly, the primary feedback that enhances the progression of Ice Ages and Interglacials is actually snow-ice-albedo, while CO2 feedbacks were, and still are, a piss in the ocean. 

Ergo - CO2 is NOT the primary regulator of Ice Age temperatures.

And remember that we have already seen that clouds have a thermostatically regulating effect on temperature, via the negative albedo of cloud formation. And the Earth's net albedo can almost be as strongly regulated by clouds, as it is by snow and ice.  Thus CO2's dribble-in-the-ocean feedback is doubly irrelevant in world temperature and climate, because the mighty cloud albedo can oppose and also overcome it:  

    A CO2 change from 180-300 ppm equals increase of      4 wm2   (globally)
    A cloud increase of 20% will result in a reduction of    16 wm2   (globally)

    Assumptions: 
    Average world insolation 340 wm2. Normal cloud reflection 80 wm2.
    

So when the puny CO2 positive feedback tries to change world temperature, it is instantly slapped down by the mighty cloud negative feedback. And so Hansen and Sato's confident assertion at the beginning of their paper is completely incorrect.  CO2 is far from being the 'largest climate forcing', and appears to be trailing in third or fourth position a long way behind Great Year insolation, albedo, and clouds.

Ergo - CO2 is NOT the primary regulator of current world temperatures.


Fig 5.
The albedo-reflection of ice and snow goes up to 85%.  So up to 85% of the northern hemisphere's 380 wm2 net insolation may be reflected by snowy land masses and ice sheets, versus about 10% for normal landmass and seas.

Fig 6.
The author standing atop the Baltoro Glacier in the Himalaya - with not a scrap of ice in sight. Any ice on the surface quickly melts because day-time temperatures are quite high - even in October at 18,000 ft altitude. This is what an ice sheet might look like, after a thousand years of dust storms (without quite so many boulders). 

Ice Age regulation:
So world climate and temperature is a bi-stable system incorporating two extremes in temperature, which is initiated by the NH Great Year spring and summer season and assisted by strong regional albedo feedbacks. And the climate and temperature at two extremes of this bi-stable system is regulated by the cloud feedback thermostat system.  

But do note that CO2 does not figure in this scenario whatsoever, because it is insignificant and easily opposed and overcome by albedo feedbacks and the cloud regulating thermostat. So it is ice and albedo that enhance and promote Ice Ages and Interglacials, not CO2.  And it is clouds that regulate the temperature during the resulting Ice Age and Interglacial periods, not CO2.  

And from this we can say with some confidence that the world will not get much warmer than it is at present, because polar ice extent and therefore NH albedo feedbacks are already at historic lows.  If ice and albedo cannot get much lower than they are now, and ice-albedo is the primary temperature feedback,  then the world cannot get much warmer.  So the shrill cries of a runaway greenhouse effect are deliberately misleading, because surface temperatures are not going to warm appreciably more than they are at present.

The Roman and Minoan warming periods were perhaps 1ºc warmer than now, no more. Indeed, in the tampered modern tamperature record 'scientists' have made the Roman and Minoan warming periods cooler than modern temperatures, because it was embarrassing to have warmer temperatures in the past when CO2 levels were lower. So we can be quite confident that the maximum albedo feedback temperature of the world is about the temperature we have now. So the shrill cries of deadly warming that will fry the world are just that - shrill cries from a new Green religion. And yet many politicians in the West are still looking at this cult-inspired deception with mouths agape, not comprehending the scale of the problem. This is called the Big Lie. It is a tried and tested technique and it catches people out because they cannot believe the audacity of it:

Quote:
If you tell a lie big enough and keep repeating it, people will eventually come to believe it. But the lie can only be maintained for such time as the State can shield the people from the political, economic (or metrological) consequences of the lie. It thus becomes vitally important for the State to use all of its powers to repress dissent, for the truth is the mortal enemy of the lie, and thus by extension, the truth is the greatest enemy of the State.
Joseph Goebbels    (My brackets.)

Fig 7.
Changes in insolation in high northern latitudes during the Great Year (Milankovitch Cycles). And the resulting worldwide surface temperature.

The missing Ice Ages:
However, the potential flaw in this ice-albedo climate feedback theory is the missing Ice Ages in the geological record, as has been mentioned previously. If the NH Great Spring and NH Great Summer seasons of the Seasonal Great Year are the initiator of Interglacials, because of their strong insolation warming influences in the higher northern latitudes, then we should surely get four Interglacials every 90,000 years, rather than one. The Great Year (GY) is 21,700 years long, and so each GY should produce a summer season (an Interglacial) and a winter season (an Ice Age). (With this effect only correlating with NH GY seasons, because of the larger NH landmasses.)

However, take a look at fig 7 again. Notice that 170,000 years ago there was a very strong Great Year summer season with an increased insolation of about 80 wm2. This greatly increased Sun-strength would surely have been enough to end an Ice Age, and yet the temperature remained stubbornly cold all the way though this GY summer season. Clearly, there must be another factor influencing and modulating these Interglacial periods besides the seasons of the Great Year, but what can it be?  Surprisingly, the answer is dust. Yes, a humble wind-blown dust storm. 

As we saw previously, the albedo of fresh snow can go as high as 85%. So no matter how hot the GY summer season is, the ice sheets and glaciers are not going to melt if they are covered by a fresh layer of snow. The net insolation at 65ºN is about 380 wm2, and so the absorption of the northern ice sheets may well be just 115 wm2 (at 70% albedo). And the GY summer insolation only adds another 25 wm2 to that (at 70% albedo). So yes, the increased insolation during the GY summer season that peaked 170,000 years ago, could well have been shrugged off by pristine snow and ice, resulting in no additional warming or melting. What an Interglacial warming period requires, in order to be successful, is a layer of dust and dirt on the ice-sheets, to reduce the albedo and allow the GY summer season to get a grip on this reflective layer and melt the ice sheets. 

Surprisingly, this is exactly what happened, as can bee seen in fig 8. This graph demonstrates that every Interglacial warming period was preceded by at least 10,000 years of dust storms (red line). In scientific journals it is sometimes claimed that this dust was derived from retreating ice-sheets leaving a barren landscape. But as we all know, plant recolonisation with grasses is likely to be rapid after ice sheets retreat, and so this explanation is highly improbable. Besides, it is indisputable that each dust era preceded the end of the Ice Age by some 10,000 years, rather than occurring during the Interglacial glacial retreat period. 

So what caused the dust-storms, that reduced the albedo and allowed the Ice Ages to end? Fig 8 gives us the answer, because it also shows that CO2 levels during each Ice Age came all the way down to 180 ppm (green line), and that is dangerously low for plant life. CO2 is probably the most important gas in the atmosphere, because it is an essential plant food. Without CO2 plants die, and if all the plants die then the entire world ecosystem dies with it. And this has been confirmed by none other than Patrick Moore, the co-founder of Greenpeace who said:

Quote, Patrick Moore:
'CO2 is lower today than it has been through most of the history of life on earth … At 150 ppm CO2 all plants would die, resulting in the virtual end of life on earth' *3

So the most likely reason for these isolated and sudden dust-storm eras, is that when CO2 reached its minimum value there was a massive dieback of vegetation.  This dieback would have caused large areas of barren ground to be exposed. And the high winds caused by the ice sheet terminus temperature difference can blow dust from those newly barren lands into the atmosphere, with much of it settling on the Arctic and Antarctic ice sheets (the ice core data in fig 8 is from Antarctica). So the barren ground was not caused by retreating ice sheets, it was caused by not enough CO2. 

But if an era of dusty conditions is required to end an Ice Age, as is quite apparent from fig 8, then this is yet further evidence that the primary feedback regulating world temperature is albedo, rather than CO2.  Dust has no connection whatsoever with world CO2 levels, but it does have a very strong correlation with world albedo strength, especially during an Ice Age. The dust layers on the ice sheets will get deeper and deeper by the century, until there is a thick layer of dust-laden ice in the upper layers of the ice sheets. And so the net result of this lack of CO2, and the barren regions and dust storms that followed, was that the critical northern latitude ice sheets had greatly reduced albedo. 

But there is one other critical requirement for the end of an Ice Age, and that is increasing insolation in the northern hemisphere during a Great Year's spring and summer. And now the GY summer sunshine could at last get some leverage on the highly reflective ice, because of its reduced dusty albedo. And the albedo of the ice sheets would have reduced even further, year by year, because the dust and dirt remains on the surface while the ice melts all around it. And so the surface dust merges with older dust from previous centuries, creating an increasingly dirty surface - until the pristine white ice sheets look more like the dusty glacial moonscape on the Baltoro glacier in fig 6. And so at last this vast sea of dirty ice could begin to warm and melt. Which is why the Interglacial warming periods in fig 7 are so closely correlated with the summer season of the Great Year and always follow a dust-storm era. 

And it was this warming Interglacial period that was the savior of all plant and animal life on the Earth. The real life-threatening aspect of CO2 is having too little of it, rather than having too much. But the increasing Interglacial temperatures eventually allowed CO2 outgassing from the oceans, which gave more food to plants and saved all plant and animal life from certain extinction. And the resulting revitalised plant growth further reduced world albedo by recolonising the barren lands, which further assisted the Interglacial warming trend. Thus the critical elements necessary for the end of an Ice Age are:

a.  CO2 reducing below 200 ppm.
b.  Wholesale plant-life die-back.
c.  Large areas of exposed barren ground.
d.  High winds that form at the ice sheet terminus.
e.  Thick dust deposited on the ice sheets, for successive centuries.
f.   Greatly reduced albedo on the ice sheets.
g.  A Great Year summer season in the northern hemisphere.

And this results in:

a.  Warming temperatures.
b.  A positive feedback were melting ice concentrates dust on the ice, giving even more warming.
b.  A positive feedback were retreating ice sheets result in less albedo and even more warming.
c.   Increasing ocean temperatures, resulting in CO2 outgassing from the oceans.
d.   Increasing atmospheric CO2 concentrations.
e.  Plant life recovering, and reducing albedo even more.

Only with all these many conditions in place, will there be a virtuous feedback cycle which can rapidly end an Ice Age. And the primary feedback that encourages this warming trend is albedo. Albedo can provide tens of extra wm2 to the all-important northern ice-sheets, while the puny CO2 molecule can do little or nothing to assist. And we know that CO2 is only a minor player in this drama, because when albedo reaches a minimum during the Interglacial era, when the ice sheets have all gone, the warming stops. So CO2 is only a bit-player in this drama, while the stars of the show are the Great Year seasons in the NH and albedo feedbacks.

This is why the Great Year summer season that peaked 170,000 years ago was completely ignored by the surface temperature - because there had been no plant-life die-back, and no dust storms.  It would appear that the world's cloud-modulating thermostat can keep the world quite stable at Ice Age temperatures, even when subjected to a northern hemisphere high latitude warming trend of plus 80 wm2.  Yes, the snow-ice albedo and the negative cloud feedbacks are that strong, that they can maintain an Ice Age in the face of very high increases in NH insolation.  

And so the Great Year summer 170,000 years ago did absolutely nothing to global temperatures. It was only after the later plant-life die-back resulting in barren regions and dust storms  -  which happened around 150,000 years ago  -  that the world was primed and ready for an Interglacial warming period. And as can be seen in fig 7, as soon as the next NH Great Year summer came along, the surface temperatures immediately responded and the Ice Age ended.    


Fig 8.
Ice Ages and dust strength, from the Vostok ice core. Note that the dust events all occur before the Interglacial warming, and so before the melting of the ice-sheets.
Post Script.  

Prior to about 1.2 million years ago, the Earth's temperature had a 41 k year cycle, as can be seen in fig 4, and so the climate was obviously following the 41 k year change in the Earth's obliquity or tilt angle. Since the Great Year is normally the dominant forcing factor in the Earth's insolation and climate, this change is peculiar. One possible reason for the effect of the Great Year seasons reducing, is that there was little or no eccentricity prior to 1.2 million years ago. The Great Year seasons can only differ in insolation and therefore temperature, when they are combined with a large orbital eccentricity. When there is no eccentricity the Earth still precesses on its axis, but all the Great Year seasons become much the same in insolation. However, why the Earth's orbit should lack eccentricity before 1.2 million years ago, is another matter entirely. 

Fig 9 shows the Earth's many orbital perturbations in past and future eras. The change in obliquity has a variable 41 k year cycle (blue line).  The orbital eccentricity has a variable 100 k year cycle (green line). And the Seasonal Great Year precessionary cycle has a short but very stable 21,700 year cycle (purple line).

If we combine the eccentricity and the precessionary Great Year cycles, the result is the Precession Index (red line). The Precession Index shows the strength of the Great Year's seasons - large oscillations mean large variations in insolation between the Great Summer and Great Winter at high latitudes.  The insolation line (black) is the changes in insolation at 65ºN, and it includes changes in obliquity.  This black line is the same as the blue line in fig 7, and shows the changes in insolation during the NH Great Summer (cycle peaks) and NH Great Winter (cycle troughs).

The recent lack of orbital eccentricity (green line) may also explain the modern extended Interglacial. Without any eccentricity there will be no NH Great Winter (cycle troughs in red line and black line), and so there will be no new Ice Age  -  because the variations in the strength of the Great Seasons depends upon there being some orbital eccentricity. But the recent stabilisation of global temperature at Interglacial levels is a bit premature, for the NH insolation has already fallen a reasonable amount and world temperature should have followed it.

There is a possible solution to this, but it would imply that the temperature line 125 k years ago in fig 7 is erroneously displaced into the past by about 5 k years. If a new Ice Age requires the full Great Year NH winter forcing, before the temperature falls, as the current situation might suggest, then the temperature fall 125 k years ago is potentially misaligned. The temperature fall into the last Ice Age should be slightly to the right of the Great Year insolation line, so that the full reduction in insolation can act upon the NH and cause the ice sheets to grow. 

This may be a possible solution. Since the researchers creating these ice core graphs are counting hundreds of thousands of ice layers, it would not be surprising to find that some of these climatic changes are not quite in their correct chronological positions. If this is so, then in the current era we may have already entered a 50 k year period of stable climatic conditions before the next Great Winter is due, as depicted on the black line. And even that Great Winter is not particularly severe. The next full blown Ice Age winter is not really due until 180,000 AD, and so human civilisation has emerged at a particularly fortuitous moment with a particularly benign climate for the next 180 k years. 

So the dire predictions of certain extinction being made by Big Green are totally FALSE. CO2 is not the great driver of world temperature, Great Year forcing and albedo feedbacks are. And CO2 is not an evil gas, it is the most essential and beneficial gas in the atmosphere. In fact, it was a lack of CO2 that nearly extinguished every form of life on Earth seven times within the last million years, and we were only saved on each occasion by a humble dust storm. 

So the only evil in this world is not in the atmosphere, it lies in the hearts of those who wish to starve plants and animals of their most essential food supply  --  CO2.      


Fig 9.
Milankovitch cycles plus a temperature record from the Vostok ice core. Note that the precessional Great Year is highly regular over time, while orbital eccentricity varies considerably. When eccentricity is at a minimum, the Great Seasons of the Great Year (the precession index) also come to a minimum. The Great Year cannot generate different Great Seasons, when there is no orbital eccentricity.

*1  Origin of the 100 kyr Glacial Cycle: eccentricity or orbital inclination?
       http://muller.lbl.gov/papers/nature.html

       Origin of the 100 kyr Glacial Cycle: eccentricity not orbital inclination?
       http://www.jstor.org/stable/42857?seq=1#page_scan_tab_content

*2   Climate Sensitivity Estimated From Earth's Climate History, James Hansen, Makiko Sato
        http://www.columbia.edu/~jeh1/mailings/2012/20120508_ClimateSensitivity.pdf
*3
       http://www.climatedepot.com/2012/07/13/greenpeace-cofounder-dr-patrick-moore-thank-goodness-we-came-along-reversed-150-millionyear-trend-of-reduced-co2-levels-in-global-atmosphere-long-live-the-humans/

There is a discussion on this paper Albedo regulation of Ice Ages,
                 with no CO2 feedbacks. at