# Maunder Minimum & Climate Change

1. Dec 18, 2018

### windy miller

We all know that our CO2 emissions will warm the planet. However I am wondering to what extent do climate models include the view that we might be heading to a new Maunder Minimum?
https://www.nextbigfuture.com/2018/11/winter-is-coming-super-grand-solar-minimum.html
Will this buy us a bit more time to sort out climate change than has been estimated or is it already included or not accepted?

Last edited: Dec 18, 2018
2. Dec 18, 2018

### Bystander

Intriguing, thank you for finding this.

3. Dec 18, 2018

### Staff: Mentor

This is the abstract of the peer-reviewed paper. I cannot see these conclusions anywhere!
Complete paper: http://iopscience.iop.org/article/10.1088/0004-637X/795/1/46/pdf
I have copyright concerns here, but found that link on a Harvard server http://adsabs.harvard.edu/abs/2014ApJ...795...46S and the publishing organization sits in Bristol UK, so it should be fine.
From the other paper the article cited: (emphasis mine)
In my opinion, this is merely another article to provide pseudo-evidence for a certain clientele. In football, sorry soccer, we call this "hit and hope" and in "handegg, sorry football, it's a "hail mary" to hope for sun activities, with a quite doubtful degree of influence on our climate. This influence is the real question to be answered! The paper, journal as well as the authors are from astronomy. Thus we are back to the old question: How severe is the impact of sun activities on our climate and how certain can we be? Everything else is not of interest here, as long as these two questions aren't finally answered.

Personally I come to a devastating conclusion, but this is only my opinion. The papers, however don't seem to support an optimistic point of view, as even a half degree (Zharkova) is already within the range of various models. Would be interesting to know how she derived these 0.5 degrees. And as far as I know are neither Hull nor Newcastle centers of climate research in GB, Norwich is.

Last edited: Dec 18, 2018
4. Dec 19, 2018

### Genava

Hi windy miller,

Here a few publications, normally all easily accessible and the last one is in open access.

On the effect of a new grand minimum of solar activity on the future climate on Earth

"Even taking into account all uncertainties in the temperature reconstruction, the forcings, and the model physics, the overall uncertainty is estimated to be at most a factor of 3, so the offset should not be larger than 0.3°C. Comparing this to the 3.7°C and 4.5°C temperature rise relative to 1961–1990 until the end of the century under the IPCC A1B and A2 emission scenarios, respectively, a new Maunder‐type solar activity minimum cannot offset the global warming caused by human greenhouse gas emissions. Moreover, any offset of global warming due to a grand minimum of solar activity would be merely a temporary effect, since the distinct solar minima during the last millennium typically lasted for only several decades or a century at most."
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL042710

Are the most recent estimates for Maunder Minimum solar irradiance in agreement with temperature reconstructions?
"[16] For all RCPs, a 21st‐century grand solar minimum with a TSI as estimated by Schrijver et al. [2011] leads to global temperatures during 2071–2100 which are by 0.04°C lower as compared to a continuing 11‐year solar activity cycle. Note that our model underestimates the temperature response to the 11‐year solar cycle [Lean and Rind, 2008], thus a temperature offset of 0.1°C is a more realistic value. The temperature offset due to a minimum with a TSI value corresponding to Shapiro et al.'s [2011] reconstruction is considerably larger (0.5°C), but rather unrealistic as shown for the reconstruction back to the Maunder Minimum. In any case, these values are smaller than the increase of global surface temperatures of 1.4–4.8°C relative to preindustrial times expected from the RCPs by 2100."
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL048529

What influence will future solar activity changes over the 21st century have on projected global near‐surface temperature changes?
"Even in the event of the Sun entering a new Maunder Minimum like activity state the climate response is very small compared to the projected warming due to anthropogenic influences (the probability of this within the next 40 years has been estimated to be 8% by Lockwood [2010]. The projected warming of the HadCM3 model for the B2 SRES scenario is 2.55 K by the end of the 21st century with respect to the end of the 20th century and using the most recent TSI reconstructions, a Maunder Minimum like future change gives relative reductions of less than 0.13 K. There is a possibility that by the end of the 21st century solar activity returns to current levels, but as we assume there is a reduction of solar activity in the near future to “normal” levels there may still be a drop in temperature relative to the projected end of century warming. A sensitivity analysis assuming that the solar cycle response is larger than climate models simulate still produces small variations over what is projected because of anthropogenic forcings only. Only when an older TSI reconstruction is used and the response of climate models to solar influence amplified are more substantial variations found that could mitigate what is still a relatively small fraction of the projected anthropogenic warming, a scenario which we cannot rule out but given the latest assessment of TSI variations and understanding of the climate system we feel is unlikely."
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011JD017013

Solar Influence on Global and Regional Climates
"Thus, these predictions show that continued solar decline will do little to alleviate anthropogenically driven global warming. However, the decline should do much to end the debate about the fraction of global warming that can be attributed to solar change. For the first time since about 1900, long-term solar and anthropogenic trends are now in opposite directions. Non-robust fits will fail sooner rather than later because of the change in solar behaviour. Thus, the next few years will give us much better estimates of the solar contribution to both global and regional climate change."

5. Dec 19, 2018

### windy miller

Thanks , very interesting

6. Jan 13, 2019

### Astronuc

Staff Emeritus
7. Jan 15, 2019

### jim hardy

I was taken by Prof Zharkova's lecture and watched the whole hour and a half.
but...
Being not a good mathematician i could not make sense of her formula
so was skeptical as to whether it really does make the curve fit clear back to Roman times........

so i decided to just wait and see.
After all , she says it'll show itself one way or the other in just a couple more years.

old jim

8. Jan 21, 2019

### DrStupid

There is a bracket missing in the formulas (maybe before the last cos). Looks like some copy & paste went wrong.

9. Jan 21, 2019

### Nik_2213

As I understand it, the forthcoming wibble may be a 'Dalton Dip' per 1880~1910, rather than a full-on 'Maunder Minimum' and 'Little Ice Age'.

Relatively short lead-time may falsify their current predictions, identify 'residuals', prompt iterations.
Hey, how long did it take for 'real' tidal prediction to develop ? And that with all the major 'players' in plain sight plus two tides per day ?

Of course, if an untimely volcano should seriously vog the low-latitude stratosphere during such 'Dip', we'll have global rather than mere regional problems.
:-(
{ apologies for terse post, quorum of cats helping me type... }

10. Jan 25, 2019

### Hernan Bonet

11. Jan 26, 2019

### Nik_2213

I've seen 'The Guardian' get so many technical opinions so skew over the years, I dare not comment further on their report.
YMMV...
/s

IIRC, those Thames 'Frost Fairs' were only possible because ice-jams backed up from the infamously narrow arches of Old London Bridge.

Also, IIRC, the debated model predicts a 'Dalton Dip, per 1880~1910, rather than a full-on 'Little Ice Age'.

The rising CO2 level may mitigate this. However, warmer oceans may produce much 'Lake Effect' snow, thick enough to be a real nuisance...

Upside, a decade should see the onset or not...

12. Jan 26, 2019

### jim hardy

Asimov suggested this cycle in the late 50's.
Arctic ocean once thawed makes for more winter snow up north, gradually increasing snow cover, raising albedo, hence cooling things until it freezes again and reduces winter snow....

Who knows ?

13. Jan 28, 2019

### WHT

Jim Hardy,
Regarding Zharkova's cosine of a cosine formula, the hint is that it comes from the Schmidt&Lipson Science(2009) article . Schmidt came up with a SW tool called Eureqa which does symbolic regression. Eureqa is no longer available but it could easily find cos(cos()) type expressions in time series data.

The next question is what does cos(cos()) even mean, as it is a rather rare formulation. I have one derivation based on a Sturm-Liouville differential equation. I will take a closer look at the Zharkova research and see if I can find any connections.

14. Jan 28, 2019

### jim hardy

Well Thanks !

Myself i wouldn't invest a whole lot of time at it

The kindly professor's math skills seem credentialed enough she could probably curve fit most any natural phenomenon back to Roman times
but she does honestly admit she's not a meteorologist...

But i enjoy following the climate debate . My Dad was a meteorologist who somewhere around 1952 (first grade for me) told me he believed the sun drives climate , so i probably suffer from "Confirmation Bias" ...

And her description of the currents deep inside the sun i found fascinating.
Again, confirmation bias on my part? My old Freshman chemistry professor was a nuclear chemist who believes to this day the sun's core is mostly iron...
Who knows ?

Thanks though for looking. I did a fair amount of searching and didn't find cosine of a cosine,
so decided to wait and see if anything comes of it.
As she said - in a very few years we'll know whether her curve extrapolated forward... and i should be around to see that !

So much interesting stuff, so little time...

I'd be really interested in whatever you find about "cosine of cosine".... If ii still had my TI99 i'd try it in BASIC.

old jim

Last edited: Jan 28, 2019
15. Jan 28, 2019

### gmax137

I fooled around with excel. It isn't exact (?) but Cos(cos(x)) is very close to 0.75+0.25 Cos (2x+pi). In other words, it is nearly a cosine function itself.

The differences are at the minimums; compare the red and the green-dashed curves. The green-dashed curve looks a little "flatter" at the bottom.

16. Jan 29, 2019

### jim hardy

I don't see a physical connection yet, but your plot is interesting.

Of course her B terms will make your brown plot taller or shorter...?

17. Jan 29, 2019

### WHT

After looking at her work some more, the cos(cos()) formulation is actually pretty straightforward, as all she is doing is a slight frequency modulation. Take a look at the combined terms cos(A t) × cos( cos(B t)) and that will expand as a main frequency A modulated by B.

She is doing this because the main sunspot frequency A changes over time and she is essentially curve fitting to that data. The tool that she used Eureqa did all the symbolic expression curve fitting.

Unfortunately Eureqa got bought off by an AI company so there is no way to exactly duplicate her results.

18. Jan 29, 2019

### jim hardy

Thanks - in principle not too dissimilar to Fourier ? At least analogous
I did notice the the Σk=1,,,,5
just tinkering with calculator has made clear what you're saying and why the result isn't zero centered.

As your chart shows, Cosine of(anything that sweeps between -1 and +1) will always be positive because the argument never reaches $\frac{\pi}{2}$ in either direction..

Often my alleged brain needs a little step-stool - Thanks !

old jim

Last edited: Jan 29, 2019
19. Jan 31, 2019

### tech99

I have noticed a news item by the BBC regarding a paper on the "little ice age" and the possible link to the killing of around 56 million people during colonisation of the Americas between about 1500 and 1600. "The Great Dying of the Indigenous Peoples of the Americas led to the abandonment of enough cleared land that the resulting terrestrial carbon uptake had a detectable impact on both atmospheric CO₂ and global surface air temperatures," Alexander Koch and colleagues write in their paper published in Quaternary Science Reviews.
A news item here: https://www.bbc.co.uk/news/science-environment-47063973