By Dr. Roy Spencer, PhD (reprinted from his blog with permission)
UPDATE (12:35 p.m. CDT 19 May 2011): revised corrections of CERES data for El Nino/La Nina effects.
While I have been skeptical of Svensmark’s cosmic ray theory up until now, it looks like the evidence is becoming too strong for me to ignore. The following results will surely be controversial, and the reader should remember that what follows is not peer reviewed, and is only a preliminary estimate.
I’ve made calculations based upon satellite observations of how the global radiative energy balance has varied over the last 10 years (between Solar Max and Solar Min) as a result of variations in cosmic ray activity. The results suggest that the total (direct + indirect) solar forcing is at least 3.5 times stronger than that due to changing solar irradiance alone.
If this is anywhere close to being correct, it supports the claim that the sun has a much larger potential role (and therefore humans a smaller role) in climate change than what the “scientific consensus” states.
BACKGROUND
The single most frequently asked question I get after I give my talks is, “Why didn’t you mention the sun?” I usually answer that I’m skeptical of the “cosmic ray gun” theory of cloud changes controlling climate. But I point out that Svensmark’s theory of natural cloud variations causing climate change is actually pretty close to what I preach — only the mechanism causing the cloud change is different.
Then, I found last year’s paper by Laken et al. which was especially interesting since it showed satellite-observed cloud changes following changes in cosmic ray activity. Even though the ISCCP satellite data they used are not exactly state of the art, the study was limited to the mid-latitudes, and the time scales involved were days rather than years, the results gave compelling quantitative evidence of a cosmic ray effect on cloud cover.
With the rapid-fire stream of publications and reports now coming out on the subject, I decided to go back and spend some time analyzing ground-based galactic cosmic ray (GCR) data to see whether there is a connection between GCR variations and variations in the global radiative energy balance between absorbed sunlight and emitted infrared energy, taken from the NASA CERES radiative budget instruments on the Terra satellite, available since March 2000.
After all, that is ultimately what we are interested in: How do various forcings affect the radiative energy budget of the Earth? The results, I must admit, are enough for me to now place at least one foot solidly in the cosmic ray theory camp.
THE DATA
The nice thing about using CERES Earth radiative budget data is that we can get a quantitative estimate in Watts per sq. meter for the radiative forcing due to cosmic ray changes. This is the language the climate modelers speak, since these radiative forcings (externally imposed global energy imbalances) can be used to help calculate global temperature changes in the ocean & atmosphere based upon simple energy conservation. They can then also be compared to the estimates of forcing from increasing carbon dioxide, currently the most fashionable cause of climate change.
From the global radiative budget measurements we also get to see if there is a change in high clouds (inferred from the outgoing infrared measurements) as well as low clouds (inferred from reflected shortwave [visible sunlight] measurements) associated with cosmic ray activity.
I will use only the ground-based cosmic ray data from Moscow, since it is the first station I found which includes a complete monthly archive for the same period we have global radiative energy budget data from CERES (March 2000 through June 2010). I’m sure there are other stations, too…all of this is preliminary anyway. Me sifting through the myriad solar-terrestrial datasets is just as confusing to me as most of you sifting through the various climate datasets that I’m reasonably comfortable with.
THE RESULTS
The following plot (black curve) shows the monthly GCR data from Moscow for this period, as well as a detrended version with 1-2-1 averaging (red curve) to match the smoothing I will use in the CERES measurements to reduce noise.
Detrending the data isolates the month-to-month and year-to-year variability as the signal to match, since trends (or a lack of trends) in the global radiative budget data can be caused by a combination of many things. (Linear trends are worthless for statistically inferring cause-and-effect; but getting a match between wiggles in two datasets is much less likely to be due to random chance.)
The monthly cosmic ray data at Moscow will be compared to global monthly anomalies the NASA Terra satellite CERES (SSF 2.5 dataset) radiative flux data,
which shows the variations in global average reflected sunlight (SW), emitted infrared (LW), and Net (which is the estimated imbalances in total absorbed energy by the climate system, after adjustment for variations in total solar irradiance, TSI). Note I have plotted the variations in the negative of Net, which is approximately equal to variations in (LW+SW)
Then, since the primary source of variability in the CERES data is associated with El Nino and La Nina (ENSO) activity, I subtracted out an estimate of the average ENSO influence using running regressions between running 5-month averages of the Multivariate ENSO Index (MEI) and the CERES fluxes. I used the MEI index along with those regression coefficients in each month to correct the CERES fluxes 4 months later, since that time lag had the strongest correlation.
Finally, I performed regressions at various leads and lags between the GCR time series and the LW, SW, and -Net radiative flux time series, the results of which are shown next.
The yearly average relationships noted in the previous plot come from this relationship in the reflected solar (SW) data,
while the -Net flux (Net is absorbed solar minus emitted infrared, corrected for the change in solar irradiance during the period) results look like this:
It is that last plot that gives us the final estimate of how a change in cosmic ray flux at Moscow is related to changes in Earth’s radiative energy balance.
SUMMARY
What the above three plots show is that for a 1,000 count increase in GCR activity as measured at Moscow (which is somewhat less than the increase between Solar Max and Solar Min), there appears to be:
(1) an increase in reflected sunlight (SW) of 0.64 Watts per sq. meter, probably mostly due to an increase in low cloud cover;
(2) virtually no change in emitted infrared (LW) of +0.02 Watts per sq. meter;
(3) a Net (reflected sunlight plus emitted infrared) effect of 0.55 Watts per sq. meter loss in radiant energy by the global climate system.
WHAT DOES THIS MEAN FOR CLIMATE CHANGE?
Assuming these signatures are anywhere close to being real, what do they mean quantitatively in terms of the potential effect of cosmic ray activity on climate?
Well, just like any other forcing, a resulting temperature change depends not only upon the size of the forcing, but also the sensitivity of the climate system to forcing. But we CAN compare the cosmic ray forcing to OTHER “known” forcings, which could have a huge influence on our understanding of the role of humans in climate change.
For example, if warming observed in the last century is (say) 50% natural and 50% anthropogenic, then this implies the climate system is only one-half as sensitive to our greenhouse gas emissions (or aerosol pollution) than if the warming was 100% anthropogenic in origin (which is pretty close to what we are told the supposed “scientific consensus” is).
First, let’s compare the cosmic ray forcing to the change in total solar irradiance (TSI) during 2000-2010. The orange curve in following plot is the change in direct solar (TSI) forcing between 2000 and 2010, which with the help of Danny Braswell’s analytical skills I backed out from the CERES Net, LW, and SW data. It is the only kind of solar forcing the IPCC (apparently) believes exists, and it is quite weak:
Also shown is the estimated cosmic ray forcing resulting from the month-to-month changes in the original Moscow cosmic ray time series, computed by multiplying those monthly changes by 0.55 Watts per sq. meter per 1,000 cosmic ray counts change.
Finally, I fitted the trend lines to get an estimate of the relative magnitudes of these two sources of forcing: the cosmic ray (indirect) forcing is about 2.8 times that of the solar irradiance (direct) forcing. This means the total (direct + indirect) solar forcing on climate associated with the solar cycle could be 3.8 times that most mainstream climate scientists believe.
One obvious question this begs is whether the lack of recent warming, since about 2004 for the 0-700 meter layer of the ocean, is due to the cosmic ray effect on cloud cover canceling out the warming from increasing carbon dioxide.
If the situation really was that simple (which I doubt it is), this would mean that with Solar Max rapidly approaching, warming should resume in the coming months. Of course, other natural cycles could be in play (my favorite is the Pacific Decadal oscillation), so predicting what will happen next is (in my view) more of an exercise in faith than in science.
In the bigger picture, this is just one more piece of evidence that the IPCC scientists should be investigating, one which suggests a much larger role for Mother Nature in climate change than the IPCC has been willing to admit. And, again I emphasize, the greater the role of Nature in causing past climate change, the smaller the role humans must have had, which could then have a profound impact on future projections of human-caused global warming.
Leif Svalgaard says: May 21, 2011 at 10:00 am
I really wish that there was a link between solar activity and climate. That would make my field all that more relevant [help improve funding too], but, alas, 400 years [almost 150,000 days] of claims have not gotten us any closer.
O yes, there is, but it is not TSI (including UV) or GCR or any of the feeble kind.
Here is a short graphic summary for you.
http://www.vukcevic.talktalk.net/CD2.htm
“Ok – so I assume, since the late 1700s had high solar activity, the Dalton Minimun period (1790-1820) was warm – or perhaps the Svensmark effect only affects the late 20th century climate?”
The warmth of the high solar activity from cycles 4 and 5 (which peaked about 1790) provided the starting point for the decline into the Dalton Minimum which lasted until 1830. A ten year or so lag is entirely consistent with those dates. There was a gradual decline in tropospheric temperatures as the ocean heat content from cycles 4 and 5 was vented to space over the subsequent 40 year period.
tallbloke says:
May 21, 2011 at 11:02 am
Having said that, Jasper’s comparison of north atlantic surface temps and Be10 deposition in Greenland is pretty convincing. I won’t bother trying to convince you though.
Perhaps reading these might educate you a bit: http://arxiv.org/find/all/1/all:+AND+webber+higbie/0/1/0/all/0/1
but “I won’t bother trying to convince you though”.
vukcevic says:
May 21, 2011 at 11:03 am
:I really wish that there was a link between solar activity and climate. ”
O yes, there is
Unfortunately, that will not convince anybody.
Stephen Wilde says:
May 21, 2011 at 11:06 am
The warmth of the high solar activity from cycles 4 and 5
cycle 5 was one of the smallest cycles ‘measured’…
Leif Svalgaard asked (May 21, 2011 at 10:24 am):
“I take the same data, detrend, smooth the prescribed way 1-2-1, and get a different result. So what is he not telling?”
Better questions would be:
1) What are you falsely assuming or misinterpreting?
2) What practical value is there in protracted hairsplitting?
Practical suggestion:
Move on to more productive (& less frivolously disruptive) pursuits than wasting informal volunteers’ limited time on the difference between the green curve and the red curve in this plot [ http://www.leif.org/research/Moscow-2000-2011-compare.png ]. Leave such hairsplitting to paid gravy train riders and show some respect for the limited time of informal volunteers.
Leif Svalgaard says:
May 21, 2011 at 11:07 am
Perhaps reading these might educate you a bit: http://arxiv.org/find/all/1/all:+AND+webber+higbie/0/1/0/all/0/1
Thanks Leif, I have already acquainted myself with various papers on the subject. There is without a doubt a variance introduced by multi-decadal oceanic cycles. However, on the longer timescale (thousands of years) and with appropriate data handling the problem is not so severe as you might think.
The correlation Jasper found between 10Be and the proxy he used for atlantic sst is excellent, and there will be a reason for that.
Leif Svalgaard says:
May 21, 2011 at 11:12 am
Unfortunately, that will not convince anybody.
‘That’ as a scientist you need to be far more specific for your opinion to have any weight.
tallbloke says:
May 21, 2011 at 11:29 am
Thanks Leif, I have already acquainted myself with various papers on the subject.
It doesn’t show at all. You should then be aware that “this implies that more than 50% of the 10Be flux increase around, e.g., 1700 A.D., 1810 A.D. and 1895 A.D. is due to non-production related increases!”
The correlation Jasper found between 10Be and the proxy he used for atlantic sst is excellent, and there will be a reason for that.
It is called ‘confirmation bias’
ej says:
May 20, 2011 at 10:48 am
So why is it that factors like this aren’t considered more? I understand the political bias in the AGW dynamics, but why don’t more “mainstream” people look at these things?
Politicians cannot tax their constituents on galactic cosmic rays. They _can_ tax them on the basis of the energy they use – glibly converted to a ‘carbon’ tax.
Politicians fund the researchers who provide the answers the politicians want and defund the researchers that provide information that is contrary to what the politicians want.
The days of the altruistic researcher working in a lonely garret are long gone. Research is a big multi-million dollar industry. It is what gets masters grads their PhDs and their professors tenure. This leads to an entirely venal approach to research and particularly research results. Research grants now quite often specify the result of the research to be delivered – if the research does not provide the results the funding politicians want and then funding ceases.
Unfortunately, academia has risen to the bait; so factors like GCR effects aren’t considered more because that is not what the funding politicians want to hear. Research at universities is no longer about finding the truth – it is about securing next year’s research funding.
I see some discussion of this:
http://arxiv.org/ftp/arxiv/papers/1003/1003.4989.pdf
These guys are using linear methods where complex methods are needed. The variation is semi-annual. This means the decadal correlations can flip sign. How on Earth are people missing this? It’s so simple.
Leif Svalgaard says:
May 21, 2011 at 11:37 am
‘confirmation bias’
Yeah Leif. “Whatever”.
Paul Vaughan says:
May 21, 2011 at 11:19 am
2) What practical value is there in protracted hairsplitting?
The disruption and derailment of fruitful conversation regarding discoveries about the natural world which imperil the consensus view.
Paul Vaughan says:
May 21, 2011 at 11:55 am
I see some discussion of this:
http://arxiv.org/ftp/arxiv/papers/1003/1003.4989.pdf
These guys are using linear methods where complex methods are needed. The variation is semi-annual. This means the decadal correlations can flip sign. How on Earth are people missing this? It’s so simple.
Thanks Paul. Have you demonstrated that graphically?
tallbloke says:
May 21, 2011 at 11:02 am
Your dating of the Dalton minimum is in error.
That doesn’t help your argument.
We know there were some cold winters in Northern Europe after 1804 We don’t know much about the rest of the world at that time. Multidecadal north-south oscillations play a part too. We’ll have to go on periods for which we have sufficiently useful data.
Such as?
“Leif Svalgaard says:
May 21, 2011 at 11:16 am
Stephen Wilde says:
May 21, 2011 at 11:06 am
The warmth of the high solar activity from cycles 4 and 5
cycle 5 was one of the smallest cycles ‘measured’…”
With respect I think that is merely a cynical diversionary strategy. Someone of your experience and knowledge should see immediately why that is so. We already agree that cycle ‘size’ is not the issue. What matters is the effect on the atmosphere of the changes in wavelength and particle quantities in relation to preceding and subsequent cycles in order to induce a warming or a cooling trend for the system as a whole.
Thus cycle 5 was about the median size (out of 23 measured, not one of the smallest so that is a subtle deceit) because it was near the beginning of a multicentury trend towards larger cycles culminating in those of the late 20th century.
However cycles 4 and 5 were larger than cycles 1,2 and 3 which appears to have been enough to speed up the recovery from the LIA for a while.
Then cycles 6,7 and 8 were smaller than 4 and 5 which was enough to induce the Dalton Minimum.
And so it went, right up to today when again there has been a tropospheric temperature effect (cessation of warming and possible commencement of cooling) during the ten years or so following the peak of cycle 23 and a deep and extended minimum at the start of cycle 24.
During the period of years after the sun started to fall from the peak of cycle 23 the AO collapsed to a record negative, the stratosphere stopped cooling, the troposphere stopped warming, ocean heat content stopped rising, the jets became more meridional, cloudiness increased and so did global albedo.
And contrary to expectations Jo Haigh has admitted that despite the quieter sun the atmosphere above 45km gained in ozone (thus warming) which led her to suggest that the consensus might have got the sign wrong for the solar effect on at least part of the atmosphere.
vukcevic says:
May 21, 2011 at 11:32 am
‘That’ as a scientist you need to be far more specific for your opinion to have any weight.
All I need to do is the submit your opinion to the funding agencies and ask them to supply me with the necessary funds to build on your work, alas, I don’t think it would do me any good. Perhaps you could do that yourself.
tallbloke wrote (May 21, 2011 at 12:09 pm):
“The disruption and derailment of fruitful conversation regarding discoveries about the natural world which imperil the consensus view.”
In the future I would like to see a blog policy addressing harassment of informal volunteers by gravy train riders. Impractical frivolity & volunteer-hour robbery need not be tolerated indefinitely. An organized response is merited.
Paul Vaughan says:
May 21, 2011 at 11:19 am
wasting informal volunteers’ limited time on the difference between the green curve and the red curve in this plot
You are hereby invited to stop wasting your time.
The importance of the difference between the curves is that the red curve is used to calibrate the forcing and if a red wiggle is twice as big as a green wiggle, the calibration is off by a factor of two.
Paul
tallbloke
10Be Greenland’s ice core records, as a proxy for anything solar, are the walk down the blind alley (cul-de-sac) of science.
John Finn says:
May 21, 2011 at 12:18 pm
tallbloke says:
May 21, 2011 at 11:02 am
Your dating of the Dalton minimum is in error.
That doesn’t help your argument.
I don’t need or want an argument.
Leif Svalgaard wrote (May 21, 2011 at 12:28 pm):
“The importance of the difference between the curves is that the red curve is used to calibrate the forcing and if a red wiggle is twice as big as a green wiggle, the calibration is off by a factor of two.”
This is a moot point since assumptions underpinning linear calibration are patently untenable.
Vuk:
Solar activity modulation, geomagnetic variation, ocean oscillations, are all phenomena with a common underlying causation. That’s why Greenland 10Be correlates well with proxies for North Atlantic SST. Seen from that perspective, the difficulty in disentangling the relative effects is less important than understanding the bigger picture.
vukcevic wrote (May 21, 2011 at 12:29 pm):
“10Be Greenland’s ice core records, as a proxy for anything solar, are the walk down the blind alley (cul-de-sac) of science.”
vukcevic, rather than continue beating a dead horse on the theme of what 10Be doesn’t represent, I can suggest more focus on identifying what it does represent. If you have insights to share on that front, please do.
Leif Svalgaard says:
May 21, 2011 at 12:28 pm
if a red wiggle is twice as big as a green wiggle, the calibration is off by a factor of two.
Your graph doesn’t show any red wiggles bigger than green wiggles.
http://www.leif.org/research/Moscow-2000-2011-compare.png
You need your windows wiping.
And you owe Roy Spencer an apology.