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Discussion > Modulation of Ice Ages via Precession and Dust-Albedo Feedbacks

Modulation of Ice Ages via Precession and Dust-Albedo Feedbacks
A new paper proving that CO2 is a minor player in the drama that is the Earth's climate.


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 CO2 is sequestered in the oceans and atmospheric concentrations eventually reach a critical minima of about 200 ppm, which 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.

https://www.academia.edu/20051643/Modulation_of_Ice_Ages_via_Precession_and_Dust-Albedo_Feedbacks


Ralph Ellis

Jan 6, 2016 at 2:47 PM | Registered Commenterralfeelis

Interesting, but is definitely NOT a rebuttal of AGW.

Jan 6, 2016 at 3:04 PM | Unregistered CommenterTheBigYinJames

>>definitely NOT a rebuttal of AGW.

CO2 is said to be the primary climate feedback during both modern and glacial ages. This paper proves that the primary feedback during the glacial age, was actually dust-albedo. Ergo, you might say, it is unlikely that CO2 is the primary feedback in the modern age.

R

Jan 7, 2016 at 12:14 PM | Unregistered Commenterralph Ellis

Ralph, it doesn't 'prove' anything and your 'ergo' is not valid. The paper may nevertheless be interesting and perhaps you should try to get it published.

Jan 7, 2016 at 12:50 PM | Unregistered CommenterRaff

>>doesn't 'prove' anything and your 'ergo' is not valid.

It is certainly a reasonable postulation, to form the basis for further research.
And the paper has been submitted for peer review, but no replies as yet.

Thanks.
R

Jan 7, 2016 at 2:28 PM | Unregistered Commenterralph Ellis

The paper has not been published in a peer-review science journal - Geoscince Frontiers. The final edition does read better than before.

http://ac.els-cdn.com/S1674987116300305/1-s2.0-S1674987116300305-main.pdf?_tid=fc351998-4139-11e6-8193-00000aab0f02&acdnat=1467562978_ee218f180e7d61c98f7ebd82912a3dec

Jul 3, 2016 at 5:32 PM | Unregistered Commenterralph ellis

"...now..."?

Jul 3, 2016 at 6:16 PM | Registered CommenterMartin A

Errr, yes -- 'now published.......'.

Sorry.

Jul 3, 2016 at 6:32 PM | Unregistered Commenterralph ellis

Just for info ralph:

Martin A and TBYJ are both highly intelligent and well qualified to offer opinions, Raff is a troll ^.^

Jul 4, 2016 at 2:51 PM | Registered CommenterDung

Ergo, you might say, it is unlikely that CO2 is the primary feedback in the modern age.

It is not. On glacial/interglaciatial timescales, CO2 is a feedback - it is released by a forced climate warming, enhancing the warming due to the increased greenhouse effects, and sequestered on a forced cooling, such as increased albedo and, according to this novel theory, changes in desertification and dust.

This is very different from digging sequestered carbon up and burning it, which produces a direct forcing. Historicially, on glacial timescales an 80 ppm change in CO2 takes about 5,000 years and is associated with a global temperature change of around 4C. We've engineered the same concentration change in about a century.

Jul 6, 2016 at 10:32 AM | Unregistered CommenterPhil Clarke

Phil Clarke, Do you have any figures for the resolution of those proxies?
You seem to be comparing apples and oranges.
That way it is easy to accidentally make spurious correlations.

Jul 6, 2016 at 10:43 AM | Registered CommenterM Courtney

>>Phil Carke.

Do you have any evidence that CO2 is the primary feedback agent during ice ages? Or are you making unsubstantiated assumptions?

And if CO2 was the primary regulator of ice ages, why does the world cool when Co2 reaches a maximum, and warm when CO2 reaches a minimum? Especially as Co2 still retains a great deal of warming potential, at 300 ppm. And why do all ice ages peak at roughtly the same temperature? Co2 cannot explain these aspects of paleoclimate.

Conversely, albedo not only tracks ice age temperatures, in a similar fashion to CO2, it also reaches a natural maximum. This is reached when the majority of the ice sheets have dissipated, and no more ice-influenced albedo changes are possible. And albedo can also warm the planet (unlike CO2), because the value of albedo can be considerably lowered by dust deposition, just as the ice-core data records.

So Co2 cannot explain the ice age cycle, while albedo can. So why do you still claim that CO2 modulates ice ages?? That seems illogical.

Ralph

.

Jul 6, 2016 at 11:17 AM | Unregistered Commenterralph ellis

Do you have any evidence that CO2 is the primary feedback agent during ice ages? Or are you making unsubstantiated assumptions?

Firstly, congratulations on passing peer review and getting this published, I think it raises an interesting and plausible hypothesis, although as your coauthor wrote at WUWT 'we can’t be sure whether this hypothesis is true'.

Do you have any evidence that CO2 is the primary feedback agent during ice ages? Or are you making unsubstantiated assumptions?

Well, presumably you do not dispute (as it is in the paper) that CO2 levels change by around 80-100ppm between glacials and interglacials, and that CO2 is a greenhouse gas of known efficacy? This may not be sufficient to explain 100% of the temperature changes, and there are significant unknowns, however I think you have some way to go before providing hard evidence that, the greenhouse-gas attributes of CO2 play little or no part in this complex feedback system.

And if CO2 was the primary regulator of ice ages, why does the world cool when Co2 reaches a maximum, and warm when CO2 reaches a minimum? 

It is not, changes in insolation from orbital changes are the primary driver, CO2 and albedo are amplifying feedbacks.


https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-4.html#6-4-1

Jul 6, 2016 at 1:36 PM | Unregistered CommenterPhil Clarke

Well, presumably you do not dispute (as it is in the paper) that CO2 levels change by around 80-100ppm between glacials and interglacials, and that CO2 is a greenhouse gas of known efficacy?

And within that huge assumption lies your error.

How do scientists know the efficacy of Co2 as a greenhouse gas? They extrapolated a warming trend, and came up with a figure. But ever since 1997, that figure has been far too high. And the warming we had in the 90s may have been more due the PDO and AMO oceanic cycles, than CO2.

In addition, the primary signal for CO2 + H2O warming is an increase in tropospheric temperature around the tropics (the increasing reradiated signal from those greenhouse gasses). And yet that signal has never been found (except by a paper that tortured the data until it screamed).

In short, there is absolutely no hard evidence that CO2 has the warming capacity claimed (about 3.5 wm2 for a doubling of CO2, if I remember correctly). So what if this figure is wrong? Have you considered that? Hansen was most cetainly wrong about the warming influence of albedo, because he spread it over the globe, which is completely illogical. What meld the winter snow in Canada - the summer Sun in Canada, or the temperature in Argentina.

Logic demonstrates that present climate science is wrong, and in need of a complete overhaul. Co2 as a feedback system cannot explain anything about the ice age cycle, while dust-ice albedo explains everything. And that gives us great confidence that the theory is true.

P.S. Michael was my mentor, rather than my co-author. Anthough I could not have completed the paper without his undoubted expertise in data analysis.

Ralph

Jul 6, 2016 at 2:58 PM | Unregistered Commenterralph ellis

In short, there is absolutely no hard evidence that CO2 has the warming capacity claimed (about 3.5 wm2 for a doubling of CO2, if I remember correctly)

This is simply wrong. The greenhouse effect of CO2 is well-established science.

http://onlinelibrary.wiley.com/doi/10.1029/98GL01908/epdf

In addition, the primary signal for CO2 + H2O warming is an increase in tropospheric temperature around the tropics (the increasing reradiated signal from those greenhouse gasses). And yet that signal has never been found (except by a paper that tortured the data until it screamed).

Try these

• Bengtsson, L. and K.I. Hodges (2009): On the evaluation of temperature trends in the tropical troposphere. Climate Dynamics, “Online First”, doi:10.1007/s00382-009-0680-y.
• Randel, W.J. and F. Wu (2006): Biases in Stratospheric and Tropospheric Temperature Trends Derived from Historical Radiosonde Data. Journal of Climate, 19, 10, 2094-2104, doi:10.1175/JCLI3717.1.
• Sherwood, S.C., et al. (2008): Robust Tropospheric Warming Revealed by Iteratively Homogenized Radiosonde Data. Journal of Climate, 21, 20, 5336-5352, doi:10.1175/2008JCLI2320.1 .
• Thorne, P.W., et al. (2007): Tropical vertical temperature trends: A real discrepancy? Geophysical Research Letters, 34, L16702, doi:10.1029/2007GL029875.
• Thorne, P.W., et al. (2010) Tropospheric temperature trends: history of an ongoing controversy. WIRES: Climate Change, in press, doi:10.1002/wcc.80.


PS, If you get chance to revise the paper, I'd advise removing the reference to Eschenbach in E&E. It's inclusion rather undermines the chances of the paper being taken seriously.

Jul 6, 2016 at 4:07 PM | Unregistered CommenterPhil Clarke

Try looking at Figure 3 of this paper. It's well known that the trigger for Milankovitch cycles is orbital forcing and that the change in temperature is then due to a combination of changes in CO2 and changes in albedo. As Phil has already said, in Milankovitch cycles, these are technically feedbacks to changes in orbital forcing. However, globally, the change in orbital forcing is small, and so the dominant changes are ultimately CO2 and albedo, which then drive the temperature changes and can be used to estimate the climate sensitivity.

Jul 8, 2016 at 12:20 PM | Unregistered Commenter...and Then There's Physics

>>This simply wrong. The greenhouse effect of CO2 is well-established science.

Not so. Scientists have derived the Co2 forcing figure from the warming and Co2 increases during the Holocene interglacial warming. However, if this warming was primarily caused by dust-ice albedo influences, then the entire concept of Co2 feedback warming is wrong. And all of the 'science' of global warming is also wrong.

What is your cast-iron proof that Co2 was responsible for interglacial warming, rather than albedo?

>>Escenbach.

Rather than attacking the man, as fantasists often like to do, please address the theory. What do you disagree with, regards the Thunderstorm Thermostant theory? Can you even understand it?

Ralph

Jul 8, 2016 at 6:07 PM | Unregistered Commenterralph ellis

>>However, globally, the change in orbital forcing is small.

Have you read the paper? Why are you smearing the effects of albedo all over the globe?

What melts the winter snow in Canada - the summer insolation in Canada, or the average temperature across the world? Do you see how the science has been distorted by illogical thinking?

In reality, the dominant factor melting the ice age ice sheets is NH insolation increases during a precessional Great Summer. And this can increase insolation by 100 w/m2 (by 200 w/m2 if you take midday insolation values). And that is a very significant increase, in comparison to the paltry effects of Co2 (which does smear itself across the world).

Ralph

Jul 8, 2016 at 6:15 PM | Unregistered Commenterralph ellis

Ralph,
Because at the end of the day - given a long enough timescale - the system should return to energy balance. A large change in orbital forcing in some region (but small globally) cannot - by itself - increase global averaged surface temperatures, because that would violate the basics of energy conservation.

Just out of interest, do you actually dispute the basic greenhouse effect?

Jul 8, 2016 at 7:38 PM | Unregistered Commenter...and Then There's Physics

>>A large change in orbital forcing in some region (but small globally)
>>cannot - by itself - increase global averaged surface temperatures,
>>because that would violate the basics of energy conservation.

Eh?? Of course it can.

a. A brief and localised insolation increase melts an ice sheet covering Canada.
b. Canada remains ice feee for the next 10,000 years.
c. Albedo of the region is considerably lower than before the melting.

Tell me - will world temperatures increase because of an ice-free Canada, or remain the same?

Ralph

Jul 8, 2016 at 7:50 PM | Unregistered Commenterralph ellis

Ralph,


A brief and localised insolation increase melts an ice sheet covering Canada.

Indeed, so it's not by itself. The melting of ice changes the albedo which changes the global energy balance.

Jul 8, 2016 at 8:13 PM | Unregistered Commenter...and Then There's Physics

>>Indeed, so it's not by itself. The melting of ice changes the
>>albedo which changes the global energy balance.

You are tying yourself in knots here.

So you are now agreeing with me. Regional insolation changes caused by a precessional Great Summer and dusty ice-sheets cause regional melting and permanent regional albedo changes, and this leads to global warming. This is what my paper says, and this is what you agree with. So you are a now supporter and promoter of my paper.

Well thank you for your support, it is much appreciated.

Ralph

Jul 8, 2016 at 8:25 PM | Unregistered Commenterralph ellis

Ralph,
If you need to tell me that I support you, that would seem to suggest that you aren't confident enough to allow me to do it myself?

Jul 8, 2016 at 8:46 PM | Unregistered Commenter...and Then There's Physics

Not so. Scientists have derived the Co2 forcing figure from the warming and Co2 increases during the Holocene interglacial warming.

Again, this is wrong, and fairly fundamental. If you read the paper I linked you will find not a single reference to Paleoclimate, the radiative forcing numbers used by the IPCC are derived from physical models.

You seem to be confusing forcing with sensitivity.

Jul 9, 2016 at 12:08 PM | Unregistered CommenterPhil Clarke

Phil,
Also, judging by Ralph's response to your earlier comment, he doesn't regard the Greenhouse effect as well-established science, which is rather odd, as it very obviously is. The surface of the Earth is - on average - 33K warmer than it would be in the absence of an atmosphere, and this is entirely due to the presence of radiatively active gases in that atmosphere. Even though CO2 does not have the dominant radiative influence in the Greenhouse effect, it is essentially the only non-precipitating GHG and hence plays a very crucial role in maintaining the greenhouse effect.

Jul 9, 2016 at 2:08 PM | Unregistered Commenter...and Then There's Physics