Global temperature response to radiative forcing: Solar cycle versus volcanic eruptions

Another one in the eye for the solarists. K. Rypdal, JGR VOL. 117, D06115, 14 PP., 2012 doi:10.1029/2011JD017283:

I show that the peak-to-peak amplitude of the global mean surface temperature response to the 11-year cyclic total irradiance forcing is an order of magnitude less than the amplitude of a cyclic component roughly in phase with the solar forcing which has been observed in the temperature record in the period 1959-2004. If this cyclic temperature component were a response to the solar forcing, it would imply the existence of strong amplifying feedbacks which operate exclusively for solar forcing, such as top-down mechanisms responding to the large variability in the ultraviolet part of the solar spectrum. I demonstrate, however, that the apparent cyclic component in the temperature record is dominated by the response to five major volcanic eruptions some of which incidentally took place a few years before solar minimum in four consecutive solar cycles, and hence that the correlation with the solar cycle is coincidental. A temperature rise of approximately 0.15 K over the 20th century ascribed to an increasing trend in solar forcing is more than offset by a cooling trend of about 0.3 K due to stratospheric aerosols from volcanic eruptions.

Or in other words, you can’t do attribution just by looking for cycles that you’d like to see in the records. That wazzock Scafetta springs to mind.

They even provide a list of Key Points:

* Solar cycle signal in global temperature is no more than 0.02 degrees K
* A 0.2 K periodic signal observed in phase with solar cycle is due to volcanoes
* Volcano cooling in 20th century more than offsets solar activity warming

Disclaimer: I’ve only read the abstract, but it seems clear enough.


* The 11 year solar cycle signal in transient simulations from the Whole Atmosphere Community Climate Model – not directly relevant, mind.

17 thoughts on “Global temperature response to radiative forcing: Solar cycle versus volcanic eruptions”

  1. Interesting. The 0.02K figure is lower than that found in other statistical treatments. I think Lean & Rind and Foster & Rahmstorf both found ~0.1K influence from max to min.

    Incidentally, your first line makes it look like the title of the paper is ‘Another one in the eye for the solarists’, perhaps recalling Einstein’s seminal 1916 work: ‘Put that in your pipe and smoke it’.

    [Not deliberate, but that’s a good connection -W]



    There’s a simple explanation as to why temperatures are not following carbon dioxide levels.

    Seeing that a microwave oven produces low frequency radiation far more intense than carbon dioxide could ever do, and yet its radiation is not absorbed* and converted to thermal energy in ice, what makes anyone think that radiation from carbon dioxide could warm all the snow and ice covered areas of the planet?

    [I’ll let this drivel stand as a fitting memorial to your intellect -W]

    The mechanism by which microwave ovens heat water molecules is totally different from the excitation of atoms which happens when high frequency solar radiation warms water. The oven emits radiation at a very specific frequency which happens to resonate with natural frequencies of the water molecules which then “snap” or “flip” through 180 degrees and back again in synchronisation with the passing waves of electromagnetic radiation. The molecules in water do have the space to do this, and when they flip there is frictional heat generated by collisions of the molecules. In ice there is not sufficient room to move and flip like this.

    There is no violation of the Second Law of Thermodynamics simply because electrical energy was added to the system.

    But the fact that the ice was not melted demonstrates the phenomenon of “resonant scattering” in which radiation is not reflected, not transmitted and not absorbed with conversion to thermal energy. See Section 5 of my publication here.

    * Try this home experiment:

    Obtain two identical small microwave bowls which do not get warm in the microwave oven. Ensure that they both fit in the oven together. Obtain a small ice cube tray and fill it with filtered or distilled water. Pour that water into one of the bowls. Then refill the tray with similar water and place the ice cube tray in your freezer and both the bowls in your frig overnight. Next day, empty the ice cubes into the bowl without water, then place both bowls in the microwave oven and operate for about 60 to 80 seconds depending on the volume of water – try to bring the water nearly to the boil. Observe that the ice has not been affected – you might even try comparing its temperature with other ice in the freezer. To do this, pack the ice samples in a tall insulated mug and insert a meat thermometer with a metal spike.

    Why wasn’t the energy in the radiation shared equally between the water and the ice? If you pour the hot water into the bowl with the ice it will easily melt the ice within a couple of minutes, so this demonstrates that sufficient energy did enter the water.



  3. so, no more climate astrology, but now climate voodoo ? Can we predict a surge of “it’s the volcanoes” soon ? They already have explored this path, after all.
    Or maybe a “the Sun drives volcanoes who drive climate”. Don’t laugh, I have already seen some people asserting that solar (or cosmic ?) rays induce heat in the Earth and thus induce tectonic activity.


  4. Soon enough, I’m sure, bratisla. I suppose the only positive aspect to all of this is that the denialists continue to feel it necessary to base their position in reasoning based on facts, however poor the reasoning and cherrypicked or made up the facts.


  5. FWIW, the frequency of the magnetron in your microwave oven (the thing that makes the waves) is not resonant with water, but will heat anything that has a dielectric moment (where there are positive and negative ends to the molecules, water being an excellent example).

    Douglas, of course, is a noted goober, with a peer reviewed paper (Eli shudders at the nature of the peers, Chris perhaps), who belongs in the ninth circle of the Burrow


  6. 6 J Bowers,

    Oh, that’s good but surely a Poe?

    BTW it looks like there’s a split in the denial camp: those who want to be seen as serious sceptics (Singer, Spencer, and even Watts) are distancing themselves from the way-out-there nutters (physics deniers like Doug Cotton and the “Slayers”).



    Nature | Letter

    Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability

    Ben B. . Booth, Nick J. Dunstone, Paul R. Halloran, Timothy Andrews & Nicolas Bellouin

    Nature (2012) doi:10.1038/nature10946
    Published online 04 April 2012

    “… inclusion of aerosol–cloud microphysical effects, which were included in few previous multimodel ensembles, dominates the magnitude (80 per cent) and the spatial pattern of the total surface aerosol forcing in the North Atlantic. Our findings suggest that anthropogenic aerosol emissions influenced a range of societally important historical climate events such as peaks in hurricane activity and Sahel drought. Decadal-scale model predictions of regional Atlantic climate will probably be improved by incorporating aerosol–cloud microphysical interactions and estimates of future concentrations of aerosols, emissions of which are directly addressable by policy actions.”

    [I think the key bit is “aerosol emissions and periods of volcanic activity explain 76 per cent of the simulated multidecadal variance in detrended 1860–2005 North Atlantic sea surface temperatures” (my bold). Since the obs over that period were clearly non-linear, that leaves a lot of variance to be explained. Not quite clear why that is new, though -W]


  8. [I think the key bit is “aerosol emissions and periods of volcanic activity explain 76 per cent of the simulated multidecadal variance in detrended 1860–2005 North Atlantic sea surface temperatures” (my bold). Since the obs over that period were clearly non-linear, that leaves a lot of variance to be explained. Not quite clear why that is new, though -W]

    I think ‘detrended North Atlantic SSTs’ is a description of the AMO, so they’re suggesting aerosols can explain 76% of the AMO. As I understand it this detrending is non-linear.

    The new part appears to be that this behaviour hasn’t been observed in previous generations of GCMs – it requres an interactive aerosol module with cloud microphysics to capture all the “indirect” and “semi-direct” processes.

    [I’m not sure I believe that, though. Aerosol cooling has been part of the std explanation for the 40’s-70’s “cooling” for more than a decade now. Still, I haven’t read the actual paper yet -W]

    Re: Roy Spencer
    Interestingly he’s stated that his analysis doesn’t have any bearing anywhere other than the US, so it doesn’t really say anything about “global” warming. He appears to be arguing for American exceptionalism.


  9. Re Booth et al. Nature, I wondered if the new part might be that they’ve described some (new?) “microphysical effects” and inference those affect “spatial patterns” — “such as hurricane activity and Sahel drought” (as in, if we emit this stuff here, it goes there and changes that).

    Being a dusty old guy I have the antiquated habit of thinking that if Nature publishes it, there ought to be something beyond academic interest in it.

    I guess the key indicator will be whether RPJr. attacks the paper.

    [That is one way. Microphysics, yes maybe, its quite hard to tell from this distance -W]


  10. Topical: the Landscheidt/John Daly claims are back, as seen in RC’s Borehole recently: “… long-range forecasts of climate phenomena, based on cycles in the sun’s orbital motion, have turned out correct, as for instance the prediction of the last three El Niños years before the respective event.” No cite, of course, was provided.


  11. “No, at least in the US, there really hasn’t been any warming except for population growth, sayeth Dr. Roy in New U.S. Population-Adjusted Temperature Dataset (PDAT), 1973-2012. Doug Cotton shows up there as well.”

    Wow, quite a claim. While the rest of the earth is warming, the US has an invisible shield that prevents warming. We will have to discover how it works. Perhaps it runs on faith?


  12. re: Roy
    Note that Roy’s results were for the contiguous US. Obviously, the effect stops at the Canadian border.


  13. If you use the KNMI Climate Explorer and look at the monthly figures for Irkutsk in Siberia since 1820 or so, you can see a clear 11 year cycle up until about 1960.
    I would love to see an explanation of this. I cannot find any comparable long term series showing the same pattern.
    Can you explain this one?

    [Not directly. But as the paper ref’d here shows, it is quite possible to get the appearance a cycle where none really exists. If there was a strong solar influence on climate you’d expect a clearly visible 11-year signal everywhere. There is, I think, a signal in the upper atmosphere – but you have to look carefully. If you see a signal at only a few locations, then likely it is just chance – after all, you expect to see such a signal by chance every now and again -W]


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