There is a new paper in Environmental Research Letters that give additional support to Henrik Svensmark’s cosmic ray hypothesis of climate change on Earth. The idea is basically this: the suns changing magnetic field has an influence on galactic cosmic rays, with a stronger magnetic field deflecting more cosmic rays and a weaker one allowing more into the solar system. The cosmic rays affect cloud formation on Earth by creating condensation nuclei. Here is a simplified block flowchart diagram of the process:
The authors of the the new paper have a similar but more detailed flowchart:
The new paper suggest that changes in the quantity of cloud condensation nuclei (CCN) are caused by changes in the cosmic ray flux:
The impact of solar variations on particle formation and cloud condensation nuclei (CCN), a critical step for one of the possible solar indirect climate forcing pathways, is studied here with a global aerosol model optimized for simulating detailed particle formation and growth processes. The effect of temperature change in enhancing the solar cycle CCN signal is investigated for the first time. Our global simulations indicate that a decrease in ionization rate associated with galactic cosmic ray flux change from solar minimum to solar maximum reduces annual mean nucleation rates, number concentration of condensation nuclei larger than 10 nm (CN10), and number concentrations of CCN at water supersaturation ratio of 0.8% (CCN0.8) and 0.2% (CCN0.2) in the lower troposphere by 6.8%, 1.36%, 0.74%, and 0.43%, respectively. The inclusion of 0.2C temperature increase enhances the CCN solar cycle signals by around 50%. The annual mean solar cycle CCN signals have large spatial and seasonal variations: (1) stronger in the lower troposphere where warm clouds are formed, (2) about 50% larger in the northern hemisphere than in the southern hemisphere, and (3) about a factor of two larger during the corresponding hemispheric summer seasons. The effect of solar cycle perturbation on CCN0.2 based on present study is generally higher than those reported in several previous studies, up to around one order of magnitude.
The wider variation in CCNs makes the Svenmark’s hypothesis more plausible since the effect on clouds would also be proportionately larger.
They conclude:
The measured 0.1% level of the longterm TSI variations on Earth’s climate (i.e., solar direct climatic effect) is too small to account for the apparent correlation between observed historical solar variations and climate changes, and several mechanisms amplifying the solar variation impacts have been proposed in the literature.
Here we seek to assess how much solar variation may affect CCN abundance through the impacts of GCR and temperature changes on new particle formation, using a global aerosol model (GEOSChem/APM) optimized for simulating detailed particle formation and growth processes. Based on the GEOSChem/ APM simulations, a decrease in ionization rate associated with GCR flux change from solar minimum to solar maximum reduces global mean nucleation rates CN3, CN10, CCN0.8, CCN0.4, and CCN0.2 in the lower troposphere (0–3 km) by 6.8%, 1.91%, 1.36%, 0.74%, 0.54%, and 0.43%, respectively. The inclusion of the impact of 0.2 C temperature increase enhances the CCN solar cycle signals by around 50%.
The annual mean solar cycle CCN signals have large spatial and seasonal variations, about 50% larger than in the northern hemisphere than in the southern hemisphere and about a factor of two larger during the corresponding summer seasons. The average solar cycle signals are stronger in the lower troposphere where warm clouds are formed. The regions and seasons of stronger solar signals are associated with the higher concentrations of precursor gases which increase the growth rate of nucleated particles and the probability of these nucleated particles to become CCN. The effect of solar cycle perturbation on CCN0.2 based on the present study is generally higher than those reported in several previous studies, up to one order of magnitude. Clouds play a key role in the energy budget of Earth’s surface and lower atmosphere.
Small modifications of the amount, distribution, or radiative properties of clouds can have significant impacts on the climate. To study the impacts of a 0.5%–1% change in CCN during a solar cycle on cloud albedo, precipitation, cloud lifetime, and cloud cover, a global climate model considering robust aerosol–cloud interaction processes is needed. It should be noted that 0.5%–1% change in CCN during a solar cycle shown here only considers the effect of ionization rate and temperature change on new particle formation. During a solar cycle, changes of other parameters such as UV and TSI flux may also impact chemistry and microphysics, which may influence the magnitude of the solar indirect forcing. Further research is needed to better quantify the impact of solar activities on Earth’s climate.
Note the bold in the last paragraph.
WUWT readers may recall that Dr. Roy Spencer pointed out the issue of a slight change in cloud cover in his 2010 book intro of The Great Global Warming Blunder: How Mother Nature Fooled the World’s Top Climate Scientists. He writes:
“The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling.”
The paper at ERL:
Effect of solar variations on particle formation and cloud condensation nuclei
Fangqun Yu and Gan Luo
The impact of solar variations on particle formation and cloud condensation nuclei (CCN), a critical step for one of the possible solar indirect climate forcing pathways, is studied here with a global aerosol model optimized for simulating detailed particle formation and growth processes. The effect of temperature change in enhancing the solar cycle CCN signal is investigated for the first time. Our global simulations indicate that a decrease in ionization rate associated with galactic cosmic ray flux change from solar minimum to solar maximum reduces annual mean nucleation rates, number concentration of condensation nuclei larger than 10 nm (CN10), and number concentrations of CCN at water supersaturation ratio of 0.8% (CCN0.8) and 0.2% (CCN0.2) in the lower troposphere by 6.8%, 1.36%, 0.74%, and 0.43%, respectively. The inclusion of 0.2 °C temperature increase enhances the CCN [cloud condensation nuclei] solar cycle signals by around 50%. The annual mean solar cycle CCN signals have large spatial and seasonal variations: (1) stronger in the lower troposphere where warm clouds are formed, (2) about 50% larger in the northern hemisphere than in the southern hemisphere, and (3) about a factor of two larger during the corresponding hemispheric summer seasons. The effect of solar cycle perturbation on CCN0.2 [cloud condensation nuclei] based on present study is generally higher than those reported in several previous studies, up to around one order of magnitude.
The paper is open access and can be downloaded here: http://iopscience.iop.org/1748-9326/9/4/045004/pdf/1748-9326_9_4_045004.pdf
h/t to The Hockey Schtick and Bishop Hill
Mark Adams says:
April 10, 2014 at 9:07 pm
I guess I have hard core D-K syndrome.
There is hope for you, real sufferers from D-K don’t know they suffer or deny it.
Mosher, there are times when you irritate me. But today your quips about fairy dust and “no…wait…” were grand and had me laughing hard enough to almost…almost…spill my glass of wine. Jolly good quips.
Thanks for the encouragement, am really do not want to be D-K or predictor of doom. I hope I am wrong and that you are correct in these matters of the Sun.
“””””…..Steven Mosher says:
April 10, 2014 at 6:59 pm
“I think Roy Spencer’s observation, that just small cloud cover changes cause very large energy unbalance effects.”
so the indetectable changes in cloud cover cause the detectable secular changes in temperature,
while the detectable secular changes in c02 cause nothing?…..”””””
Not a persuasive argument there Steve. There’s that old saw:
Absence of proof is not proof of absence.
You say “indetectable changes in cloud cover.”
I’ll cut you some slack and ignore the typos, I do it all the time.
But be honest it is “undetected” cloud changes that bother you; not “undetectable” cloud changes.
The cloud changes themselves maybe undetected by us, but not by planet earth, which monitors cloud cover 24 / 7 / 365.25 and over every square inch of the earth surface; and Wentz et al say the precipitation has increased (due to a small Temperature rise during their experiments), and increased precipitation guarantees there was increased cloud cover.
You cannot observe that for which you have no apparatus capable of observing.
And we have NO means of continuously and continually monitoring total earth cloud cover from the underside, which is where the precipitation comes from.
But planet earth does.
My internet security keeps on telling me that WUWT is a persona non grata website, and it constantly expunges it from my table of favorites: What gives ??
No problem Mark.
I just wasted the past couple months looking through piles of data and finding nothing.
I know when I finally find a GCR signal it will be in the last place I look.. hehe kinda like lost car keys..
Although vuk has a nice little event.. maybe that can provide some clues for isolating.
The question is when am I done?
logically, one could hold on to the thesis forever.
lsvalgaard writes, “The problem with this kind of papers is that they ignore that solar activity and cosmic ray flux have not varied much [apart form the obvious 11- and 100-yr cycles] the past 300 years, while the climate has. For example, we are currently down to the same level of solar activity as a century ago, but the climate now is not what it was back then.”
That is kind of a weak argument. The last time if got very cold after the well referenced Medieval warm period was during the Maunder Minimum. What caused the Maunder Minimum? Some say it was volcanic yet volcanic events should not have that much impact. The other thing that happened was the lack for years of almost all sun spots indicating a relatively weak sun.
Assume that when the sun has very low solar cycles that there is a larger cosmic ray flux and that this does have an impact on cloud formation – Svensmark’s theory. But cosmic ray flux is not the only thing impacting climate. Perhaps during typical solar cycles, the relative warming/cooling from changes in cosmic ray flux are lost in the noise of normal climate variation – but during very low solar cycles, the impact on clouds is relatively larger. So, along with changes in TSI and solar spectrum this can account for some amount of the cooling.
I’ve read the paper and based on it think that the authors evidence is not that convincing. But I don’t think that means that Svensmark’s theory is incorrect. Nor do I know of a better theory. Therefore, my conclusion is that more work is needed to substantiate it better, disprove it or come up with a better theory.
BobG says:
April 10, 2014 at 10:21 pm
For example, we are currently down to the same level of solar activity as a century ago, but the climate now is not what it was back then.”
That is kind of a weak argument.
It is much stronger than Svensmark’s claim based on only two recent solar cycles. You really can’t have it both ways.
But I don’t think that means that Svensmark’s theory is incorrect
It has been falsified, what more to say?
It is not up to us to disprove his ‘theory’ [Mother Nature did that already], but to him to prove it, and there he has failed. That some people still think that the theory is good sounds more like wishful thinking to me [“what else can it be?” “I don’t know of any better”, etc]. The evidence so far as amply discussed in the post does not lend credence to the Cosmic Ray HYPOTHESIS. Not a theory, mind you.
Apologies for being late to this party.
A Forbush Decrease can have an immediate (in climate terms) effect.
http://www.astrophys-space-sci-trans.net/7/315/2011/astra-7-315-2011.html
Specific conditions are spelled out in the paper.
Presumably the effect is of changed GCRs on clouds.
To dismiss Svensmark’s theory because there isn’t a linear correlation in what is acknowledged to be a complex coupled non-linear system strikes me as being a large step too far.
How about we keep a collective open mind and see where the real science takes us?
Dr Norman Page says:
April 10, 2014 at 10:58 am
I looked at Figure 8. In answer to your question “what’s not to like”, I don’t like the total absence of any source for the neutron count. I don’t like the lack of units for the neutron count. I don’t like the lack of a source for the 9,000 year reconstruction of the “Geomagnetic Dipole Field”. I don’t like the fact that the dipole field is different than the dipole moment, which is what I suspect they are actually measuring. I don’t like the fact that they are appearing to try to establish a correlation between cosmic rays and sunspots, but they don’t provide any correlation analysis. I don’t like that there is no provenance for the sunspot data. I don’t like the fact that they don’t give any source for the graph itself.
I don’t like the fact that you claim that figure 8 shows what you call the “connection between cosmic rays and temperature” when Figure 8 says nothing about temperature at all.
And finally, I don’t like going on a wild goose chase to examine a piece of uncited unscientific junk that has nothing to do with the topic under discussion. Next time, don’t bother.
Don’t know if that fully answers your question, but it’ll do for a start …
w.
lsvalgaard
The cosmic ray-cloud hypothesis is based on sound physics but observational validation is lacking, so far. To quote Jeffrey Pierce, an aerosol scientist:
“we must understand the physical basis of how cosmic rays may affect clouds. However, it is clear that substantially more work needs to be done before we adequately understand these physical connections, and that no broad conclusions regarding the effect of cosmic rays on clouds and climate can (or should) be drawn from the first round of CLOUD results.”
http://www.realclimate.org/index.php/archives/2011/09/cosmic-rays-and-clouds-potential-mechanisms/
Dr. Strangelove says:
April 10, 2014 at 11:47 pm
The cosmic ray-cloud hypothesis is based on sound physics but observational validation is lacking, so far.
Well, if it is not observed, it is clearly not an important factor, regardless of the sound physics
Mike Jonas says:
April 10, 2014 at 10:59 pm
To dismiss Svensmark’s theory because there isn’t a linear correlation in what is acknowledged to be a complex coupled non-linear system strikes me as being a large step too far.
Svensmark himself claimed there were such a linear correlation.
Willis most of your questions are answered in the original Steinhilber paper and supporting data which was linked to in the post on my site.
“Furthermore Fig 8 shows that the cosmic ray intensity time series derived from the 10Be data is the most useful proxy relating solar activity to temperature and climate. – see Fig 3 CD from Steinhilber
http://www.pnas.org/content/early/2012/03/30/1118965109.full.pdf
As to the temperature you failed ( somewhat surprisingly) to catch the significance of the letters OWSMD on the figs These correlate the cosmic ray intensities peaks to the well documented temperature minima in the last 1000 years.
These also correlate quite well with the temperature minima seen in Fig 3 of the same link.
http://climatesense-norpag.blogspot.com/2013/10/commonsense-climate-science-and.html
I wonder why you are so resistant to accepting the significance of these correlations connecting solar activity to temperature.- at least as a perfectly reasonable useful working hypothesis.
Dr Norman Page says:
April 11, 2014 at 6:13 am
These correlate the cosmic ray intensities peaks to the well documented temperature minima in the last 1000 years.
Apart from the correlation not being very good [e.g. slide 20 of http://www.leif.org/research/Does%20The%20Sun%20Vary%20Enough.pdf ], there is now a growing acceptance of the fact that the cosmic ray record is contaminated by the climate. You see, most of the 10Be in ice cores was not formed over the ice, but at lower latitudes and then by atmospheric circulation brought up to high latitudes for deposition.
lsvalgaard wrote, “It is not up to us to disprove his ‘theory’ [Mother Nature did that already], but to him to prove it, and there he has failed. That some people still think that the theory is good sounds more like wishful thinking to me.”
With respect to wishful thinking, I thought the same after reading your PPT, “Has the Sun’s Output Really Changed Significantly Since the Little Ice Age”. There seemed to be some wishful thinking that the sun’s output could not be responsible for changes in temperature. Especially the first conclusion on page 21 of the PPT, “Variation in Solar Output is a Factor of ten too Small to Account for The Little Ice Age … ” I think your conclusion based only on TSI (if error range were added ) is fairly robust. But you don’t account for the impact of variation in ultra-violet radiation or changes in cosmic rays. This is part of solar output. In your assumption about temperature changes,you don’t account for the fact that there are short term changes in climate driven by such things as the PDO, NAO and etc. that are not necessarily correlated with solar changes at least in the short term. There are also short term impact of volcanoes. Which means that it would be expected that there would be quite a bit of short term variation between the solar changes and temperatures but long term, if the hypothesis of Svensmark is correct, then longer term trends in temperature would be impacted.
BobG says:
April 11, 2014 at 9:43 am
With respect to wishful thinking, I thought the same after reading your PPT, “Has the Sun’s Output Really Changed Significantly Since the Little Ice Age”.
I go with what the data shows, not with what I believe must be happening. And have no dog in the race. I would be delighted if it could be shown that the Sun is a major driver as that would make my work [and funding] much more relevant. After having studied this hard for 40 years, I, unfortunately, cannot with my integrity intact pretend to my funding agencies that my work is of major relevance for the Climate.
The ultraviolet radiation we have a good record of back to 1722 [when its impact on the ionosphere was discovered] and neither that nor the cosmic ray record support the notion that solar activity is important. This does not mean that there is no impact. There MUST be simply because of the 0.1% of TSI, namely to the tune of 0.1 degrees, which many people claim can actually be seen in the temperature record, albeit with difficulty as the noise is large.
In respond to name calling:
lsvalgaard says:
April 10, 2014 at 7:43 pm
(See above comment for name calling.)
William:
Name calling is not a substitute for observational data and logic to support your position.
There is cyclic warming and cooling in the paleo record. (Fact, both poles see paper below that notes there is cyclic warming and cooling in the Southern hemisphere in the same region that warmed in the last 70 years) The cyclic warming and cooling in the paleo record correlates with solar magnetic cycle changes. (Fact)
As you note, the solar magnetic cycle has suddenly and unexpectedly changed. There is now unexplained cooling of the planet both poles based on increased sea ice. (Fact)
http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.global.png
http://wattsupwiththat.com/reference-pages/sea-ice-page/
http://nsidc.org/data/seaice_index/images/daily_images/S_stddev_timeseries.png
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
http://wattsupwiththat.files.wordpress.com/2012/09/davis-and-taylor-wuwt-submission.pdf
Davis and Taylor: “Does the current global warming signal reflect a natural cycle”
…We found 342 natural warming events (NWEs) corresponding to this definition, distributed over the past 250,000 years …. …. The 342 NWEs contained in the Vostok ice core record are divided into low-rate warming events (LRWEs; < 0.74oC/century) and high rate warming events (HRWEs; ≥ 0.74oC /century) (Figure). … ….The current global warming signal is therefore the slowest and among the smallest in comparison with all HRWEs in the Vostok record, although the current warming signal could in the coming decades yet reach the level of past HRWEs for some parameters. The figure shows the most recent 16 HRWEs in the Vostok ice core data during the Holocene, interspersed with a number of LRWEs. …. ….We were delighted to see the paper published in Nature magazine online (August 22, 2012 issue) reporting past climate warming events in the Antarctic similar in amplitude and warming rate to the present global warming signal. The paper, entitled "Recent Antarctic Peninsula warming relative to Holocene climate and ice – shelf history" and authored by Robert Mulvaney and colleagues of the British Antarctic Survey ( Nature , 2012, doi:10.1038/nature11391),reports two recent natural warming cycles, one around 1500 AD and another around 400 AD, measured from isotope (deuterium) concentrations in ice cores bored adjacent to recent breaks in the ice shelf in northeast Antarctica. ….
Greenland ice temperature, last 11,000 years determined from ice core analysis, Richard Alley’s paper. William: As this paper shows there the Greenland Ice data shows that have been 9 warming and cooling periods in the last 11,000 years.
http://www.climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20with%20CO2%20from%20EPICA%20DomeC.gif
lsvalgaard says:
April 10, 2014 at 1:07 pm “We are discussing the Svensmark mechanism, and Svensmark does not invoke any ‘lag’ or delay. His effect in (is) immediate.”
Where I live, when the sun comes up in the morning it warms up, when it goes down the temperature cools. It has an immediate affect. 🙂 Where I live, when a cloud passes between me and the sun, it immediately is cooler. …but that’s where I live. Not sure why there is all the discussion that seems to suggest the sun has no affect on climate or climate change. Get real.
I let the record show that we are globally cooling
http://www.woodfortrees.org/plot/hadcrut4gl/from:1987/to:2014/plot/hadcrut4gl/from:2002/to:2014/trend/plot/hadcrut3gl/from:1987/to:2014/plot/hadcrut3gl/from:2002/to:2014/trend/plot/rss/from:1987/to:2013/plot/rss/from:2002/to:2013/trend/plot/hadsst2gl/from:1987/to:2014/plot/hadsst2gl/from:2002/to:2014/trend/plot/hadcrut4gl/from:1987/to:2002/trend/plot/hadcrut3gl/from:1987/to:2002/trend/plot/hadsst2gl/from:1987/to:2002/trend/plot/rss/from:1987/to:2002/trend
So, as the temperature differential between the poles and equator grows larger due to the cooling from the top, very likely something will also change on earth. Predictably, there would be a small (?) shift of cloud formation and precipitation, more towards the equator, on average. At the equator insolation is 684 W/m2 whereas on average it is 342 W/m2. So, if there are more clouds in and around the equator, this will amplify the cooling effect due to less direct natural insolation of earth (clouds deflect a lot of radiation). Furthermore, in a cooling world there is more likely less moisture in the air, but even assuming equal amounts of water vapour available in the air, a lesser amount of clouds and precipitation will be available for spreading to higher latitudes. So, a natural consequence of global cooling is that at the higher latitudes it will become cooler and/or drier.
So why would I need Svensmark’s theory if pure practical physics can do the same job?
Lsvalgaard, Thank you for taking the time to respond. Your responses are always very illuminating.
Our global simulations
You quote a simulation study as new knowledge? You surprise me.
There is a confounding variable and that is ozone layer breakdown over last few decades.
stevek says:
April 11, 2014 at 2:30 pm
Since stratospheric ozone is mostly produced by short-wave ultraviolet rays (UVC band), natural variation in UV is largely under solar control.
Leif – Link?
William Astley says:
April 11, 2014 at 11:51 am
Name calling is not a substitute for observational data and logic to support your position.
One must a spade a spade. I don’t need to support my position as opposed to yours. Everyone of your ideas is wrong. We have been down every one of the roads and you have learned nothing, so as I said “enjoy your fantasy ride”.
Mike Jonas says:
April 11, 2014 at 4:36 pm
Leif – Link?
To what?