(Via the Hockey Schtick) A new peer reviewed paper published in The Holocene finds a significant link between solar activity and climate over the past 1000 years. According to the authors:
“Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima.”
The authors also find “a link between the 11 yr solar cycle and summer precipitation variability since around 1960” and that:
“Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity.”
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IRBSi is the proxy for precipitation/climate change and shows good agreement with solar activity. Figure 12. The comparison between the graphs of the IR-BSi and that of the solar cycles shows good agreement between the percentage of mineral materials of allochthonous and solar cycles reconstructed on the basis of changes in concentrations of 14 C in macrofossils. A good agreement is also evident between the concentrations of 18 O of foraminifera in the Norwegian Sea and the index IR-BSi. |
Solar forcing of climate during the last millennium recorded in lake sediments from northern Sweden
U Kokfelt University of Copenhagen, Denmark
R Muscheler Lund University, Sweden
Abstract
We report on a sediment record from a small lake within the subarctic wetland complex Stordalen in northernmost Sweden covering the last 1000 years. Variations in the content of minerogenic material are found to follow reconstructed variations in the activity of the Sun between the 13th and 18th centuries. Periods of low solar activity are associated with minima in minerogenic material and vice versa. A comparison between the sunspot cycle and a long instrumental series of summer precipitation further reveals a link between the 11 yr solar cycle and summer precipitation variability since around 1960. Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity. Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima, causing dry conditions with resulting decreased runoff.
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Recall that a paper published last year in Astronomy & Astrophysics shows solar activity at end of 20th century was near highest levels of past 11,500 years.
A paper published by a researcher at Max-Planck-Institute in Astronomy & Astrophysics reconstructs solar activity over the Holocene and finds solar activity at the end of the 20th century was near the highest levels of the entire 11,500 year record. The reconstruction spans the past 2,500 years, and the paper shows a ‘hockey stick’ of solar activity, following the end of the Little Ice Age in the 1800’s.
Fig. 11. TSI weighted reconstruction since approximately 9500 BC. In order to provide a better visualization, the evolution since 1000 BC is displayed in panel (b). The filled gray band represents region limited by the KN08-VADM and KC05-VDM reconstructions.
For reference, the red lines represent the 10-year averaged reconstruction by Krivova et al. (2010a).
Evolution of the solar irradiance during the Holocene
L. E. A. Vieira1,2, S. K. Solanki1,3, N. A. Krivova1 and I. Usoskin4
Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany
Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E/CNRS), 3A, Avenue de la Recherche, 45071 Orléans Cedex 2, France
School of Space Research, Kyung Hee University, Yongin, Gyeonggi, 446-701, Korea
Sodankyla Geophysical Observatory (Oulu Unit), POB 3000, Universiy of Oulu, Finland
Abstract
Context. Long-term records of solar radiative output are vital for understanding solar variability and past climate change. Measurements of solar irradiance are available for only the last three decades, which calls for reconstructions of this quantity over longer time scales using suitable models.
Aims.
We present a physically consistent reconstruction of the total solar irradiance for the Holocene.
Methods.
We extend the SATIRE (Spectral And Total Irradiance REconstruction) models to estimate the evolution of the total (and partly spectral) solar irradiance over the Holocene. The basic assumption is that the variations of the solar irradiance are due to the evolution of the dark and bright magnetic features on the solar surface. The evolution of the decadally averaged magnetic flux is computed from decadal values of cosmogenic isotope concentrations recorded in natural archives employing a series of physics-based models connecting the processes from the modulation of the cosmic ray flux in the heliosphere to their record in natural archives. We then compute the total solar irradiance (TSI) as a linear combination of the jth and jth + 1 decadal values of the open magnetic flux. In order to evaluate the uncertainties due to the evolution of the Earth’s magnetic dipole moment, we employ four reconstructions of the open flux which are based on conceptually different paleomagnetic models.
Results.
Reconstructions of the TSI over the Holocene, each valid for a different paleomagnetic time series, are presented. Our analysis suggests that major sources of uncertainty in the TSI in this model are the heritage of the uncertainty of the TSI since 1610 reconstructed from sunspot data and the uncertainty of the evolution of the Earth’s magnetic dipole moment. The analysis of the distribution functions of the reconstructed irradiance for the last 3000 years, which is the period that the reconstructions overlap, indicates that the estimates based on the virtual axial dipole moment are significantly lower at earlier times than the reconstructions based on the virtual dipole moment. We also present a combined reconstruction, which represents our best estimate of total solar irradiance for any given time during the Holocene.
Conclusions.
We present the first physics-based reconstruction of the total solar irradiance over the Holocene, which will be of interest for studies of climate change over the last 11 500 years. The reconstruction indicates that the decadally averaged total solar irradiance ranges over approximately 1.5 W/m2 from grand maxima to grand minima.
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What I find interesting is that the 1.5 W/m2 isn’t far from the value for CO2 forcing reported by CDIAC here:
http://cdiac.ornl.gov/pns/current_ghg.html
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The case against AGW just gets stronger and stronger. Love it.
An article of great interest, but not useful in the CAGW debate, unfortunately.
Variations in TSI as noted are sufficient but not necessary for the late 20th century warming: this is the problem of combating CAGW. It’s the “many roads to Mecca” problem. CO2 by IPCC narrative is sufficient to account for modern warming. Other possible means of warming, even if of historical importance, once discounted for the present, are not considerations in the argument.
So far the unique attributes of CO2 warming, the mid-tropospheric “hotspot”, the temperature rise in conjunction with CO2, are staggering around in the minimal range, allowing the warmist to believe that, with time, the comparison of expectations to observations will improve. To date, there are no unique TSI or (as I suspect) heat redistribution or other, non-CO2 signs we can point to for the skeptical defense.
We need something in this line.
Wasn’t the CO2 lifetime in the atmosphere at 100 years dropped/debunked to something closer 5, maybe 10?
Counting down for Lief to come in and comment … 3, 2, 1…
The question as to whether or not the 20th century is really a grand solar maximum as indicated by at least sunspot count is (apparently) open and debatable, given that Ushokin and colleagues steadfastly seem to disagree with Lief in this regard. The paper above seems to be quite recent and appears to (again) rely on radioactive proxies, with some control for our lack of certainty concerning the relative contribution from solar magnetic and geomagnetic screenings.
The other interesting thing to do would be to plot Ushokin’s result above against global temperature estimates over the Holocene, and then look at multivariate linear models (at least) including at least a few computable functions, such as the precession of the axis of rotation over that same timescale.
Anybody got any popcorn?
rgb
As usual, people are willing to paper over the obvious discrepancies to support whatever cause they adhere to. Overlaying the two reconstructions of solar activity shown in this post shows the problem:
http://www.leif.org/research/Last-1000-Years-Solar-Modulation.png
The brown curve [Muscheler] shows no long-term trend since 1700 consistent with sunspot and geomagnetic data. The 18th century was as active [or even more] as the 20th. The red curve [Solanki] shows the ‘most active in 10,000 years’ myth. Clearly both curves cannot be correct, yet both are taken as support. Go figure.
There is substantial evidence that some of the ‘dips’ in solar activity measured with radionuclides are not representative of solar modulation but:
“This is a particular problem for historical projections of solar activity based on ice core measurements which assume a 1:1 correspondence. We have made other tests of the correspondence between the 10Be predictions and the ice core measurements which lead to the same conclusion, namely that other influences on the ice core measurements, as large as or larger than the production changes themselves, are occurring. These influences could be climatic or instrumentally based.”
http://arxiv.org/ftp/arxiv/papers/1004/1004.2675.pdf
Anthony Watts:
“… the paper shows a ‘hockey stick’ of solar activity, following the end of the Little Ice Age in the 1800′s.”
I see an equally large ‘hockey-stick’ jump at 9000BC. Also smaller ones around 8000BC, 7000BC, 3500BC, 700BC and 350BC etc. I think these multiple occurrences, if valid, dismantle all of the AGW/CAGW “what-else-could-it-be?” arguments, because it would no longer be possible to characterize any modern hockey-stick as “unprecedented”.
Wasn’t the CO2 lifetime in the atmosphere at 100 years dropped/debunked to something closer 5, maybe 10?
According to who? There are many models that can fit the data (including the Bern model with its long lifetime). The problem is once again the difficulty of resolving the models. Fluctuation-dissipation is really the only possible way to do so, and sadly global CO_2 increases like a very nearly smooth function with a small annual/seasonal sawtooth. To get good measurements one would have to do something like inject a huge bolus of CO_2 into the atmosphere all at once and then watch how long it takes to decay back to quasi-equilibrium, or introduce in some other way a large enough fluctuation that the dissipation information would tell you something about timescales of the underlying equilibration ODEs.
Bart and Richard have done something of that (and I dabbled with it too, using octave to generate simple model fits) on another thread a year or so ago. I’d say that it is fair(er) to say that the Bern model is neither verified by any particular set of observations nor falsified by others; it remains a candidate, but there are indeed other models that make a fair bit of physical sense that would produces a much shorter equilibration time and indicate a much shorter effective lifetime.
Part of the difficulty is knowing exactly how to set the parameters that indicate what the ocean is doing. as it is the great CO_2 source/sink that keeps CO_2 levels roughly stable. It is assumed that it takes a very long time for CO_2 absorbed in the warmer surface waters to be transported to the colder waters underneath and/or biologically or chemically sequestered, but I’m not sure how much experimental evidence there is for the rates that they assign. It is a problem of the same sort as plagues the GCMs (and indeed, is an implicit plaguey component of the GCMs). If you assume that you know what is going on, you can probably find a model that works decently because CO_2 is monotonically and smoothly increasing, so that many systems of ODEs describing CO_2 uptake and release can reproduce the base shape of the increase within reasonable ranges of their parameters. But the lack of uniqueness or even similarity of the models that can reproduce the observations, and the very different interpretations of the important physics and chemistry of those models, complicate the confirmation or rejection of any of them.
rgb
This is a little O/T, but every time I have asked an AGW believer what they think the optimum range for CO2 in the atmosphere is they have ducked it. They want to reduce CO2 levels, but they have no idea to what.
My understanding (as an ecologist) is that below 220ppm a slow-down in plant growth is significantly noticeable and below 150ppm most plants stop growing.
RHS says:
January 2, 2013 at 11:39 am
Wasn’t the CO2 lifetime in the atmosphere at 100 years dropped/debunked to something closer 5, maybe 10?
No. There is, however, a great deal of confusion on this issue. It is true that the average lifetime of an individual molecule of CO2 in the atmosphere is about 5 or so years but that is not is not really the point of interest. The key statistic is the time taken for the atmospheric CO2 concentration to return to a previous level following a ‘pulse’ of increased CO2 such as that we have seen over the past 100 years or so. The basic relevant question is: how long would it take for CO2 concentrations to return to pre-industrial levels (280 ppm) if human contributions ceased.
Peter Dietze provides a reasonable estimate on the John Daly site. He finds the half lifetime of the pulse is ~38 years and that around 37% would remain in the atmosphere after 55 years. Theoretically, some of the added CO2 (see ** below) could still be present after 100 or even 200 years but this will only be a few ppm above the pre-industrial ‘equilibrium’ level.
** the “added CO2” won’t necessarily be human produced CO2. It may well be naturally emitted CO2 which hasn’t been re-sequestered because the natural uptake limit has been ‘satisfied’ by the human (+ natural) contribution.
Impossible…the UN has already declared that the sun has nothing to do with climate.
“As usual, people are willing to paper over the obvious discrepancies to support whatever cause they adhere to. (Dr. Svalgaard) Epistemologists that I read note the post-modern conception of logic as arguing from the conclusion to the supporting premises only.
lsvalgaard says: January 2, 2013 at 11:59 am
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So how reliable is 10 Be as a proxy?
mpainter says:
January 2, 2013 at 12:38 pm
So how reliable is 10 Be as a proxy?
10Be is a reliable proxy for the combined effect of the Earth’s magnetic field, Climate [atmospheric circulation], and Solar Activity. Separating the three sources is very hard. Many more ice cores from different locations may be needed. Another problem is that the theoretical underpinning for turning cosmic ray modulation into solar activity is on shaky ground. On danger of being too technical, the so-called ‘modulation parameter’ is computed based on an assumption we know is wrong, namely that the solar wind is spherical symmetric [i.e. the same in all directions from the sun]. This assumption may be reasonable at high solar activity [e.g. at solar maximum], but is demonstrably wrong at low activity, e.g. http://www.leif.org/research/A%20View%20of%20Solar%20Magnetic%20Fields,%20the%20Solar%20Corona,%20and%20the%20Solar%20Wind%20in%20Three%20Dimensions.pdf
Doug Huffman says:
January 2, 2013 at 12:37 pm
Epistemologists that I read note the post-modern conception of logic as arguing from the conclusion to the supporting premises only.
and even accepting conflicting premises as being equally valid…
Re: rgbatduke
There is a problem with the bern model and that is CO2 mixing. The model assumes that CO2 is well mixed to begin with (no problem with that), but from then on there is no mixing of CO2 whatsoever. According to model the CO2 stays with whatever sink it happens to be at at the start. This leads to the ridiculous situation whereby 13.7% is supposed to remain in the atmosphere forever. (see http://unfccc.int/resource/brazil/carbon.html).
Everything you need to know is already there. You know approximately how much CO2 enters the atmosphere from natural sources every year (about 770Gt), and what the equilibrium point is (278ppm or 2173Gt). From these two numbers you can calculate the half life:
2173 * ln(2)/770 = 2 years.
Of course the 2 year half life will be affected by temperature and probably many other factors but it shouldn’t vary much from the 2 years.
One final point, if you use the equations from the bern model to calculate how much CO2 is left after 1 year and then feed that back into the equations as a starting point (in other words remix the CO2 every year) you get a half life of about 6 years.
Looking at the scale, are we really talking about a difference of just over 1 w/m2?
Tom in Florida says:
January 2, 2013 at 1:01 pm
Looking at the scale, are we really talking about a difference of just over 1 w/m2?
Yes, but remember that the faithful invoke an unknown mechanism to amplify the impact of that tiny difference by ten times in their attempts to make it fit the observed temperature fluctuations.
fretslider says:
January 2, 2013 at 12:17 pm
This is a little O/T, but every time I have asked an AGW believer what they think the optimum range for CO2 in the atmosphere is they have ducked it. They want to reduce CO2 levels, but they have no idea to what.
My understanding (as an ecologist) is that below 220ppm a slow-down in plant growth is significantly noticeable and below 150ppm most plants stop growing.
>>>>>>>>>>>>>>>>>>>>>>>>
Yes that is certainly the fly in the ointment the zealots try to ignore. Check out the paper: Carbon starvation in glacial trees recovered from the La Brea tar pits, southern California. and Chemical Laws for Distribution of CO2 in Nature
Given the earth is cooling over the long term not warming, I much prefer more CO2 to less CO2.
The fact we can now grow twice the wheat or corn on the same acreage is a CO2 benefit that should normally be greeted with glee instead of squirming to negate it.
If you want to be taken seriously, don’t name your model SATIRE.
RHS says:
January 2, 2013 at 11:39 am
Wasn’t the CO2 lifetime in the atmosphere at 100 years dropped/debunked to something closer 5, maybe 10?
Two different lifetimes: the around 5 years lifetime is the average time that a CO2 molecule of any origin resides in the atmosphere before being exchanged with a CO2 from another reservoir (mainly oceans and vegetation). The 100 years (Bern model for the bulk of CO2) is how long it takes for some extra CO2, whatever its origin, above equilibrium to return halfway back to equilibrium. In the first case, the throughput of CO2 is important: some 150 GtC/year of CO2 is exchanged back and forth between the oceans/vegetation at one side and the atmosphere. Partly continuous (warm equatorial upwelling, cold polar downwelling), partly seasonal in the mid-latitude oceans and vegetation. That gives a turnover of 150/800 or ~20%/year or a residence time for any CO2 molecule of about 5 years. In the second case, the current sink rate is ~4 GtC/year, partly into vegetation, partly into the (deep) oceans. That is caused by an increased pressure of CO2, currently some 210 GtC (100 ppmv) above the long term temperature dictated equilibrium. That gives an e-fold time of 210/4 or 52.5 years or a half life time of the extra CO2 of ~40 years. Quite a difference with the 5 years residence time or the 100 years from the Bern model. The latter includes saturation of the deep oceans. That may be right when we reach 3000-5000 GtC releases (currently we are at 370 GtC accumulated fossil fuel use). But there are no signs that the deep oceans are saturated and certainly no signs that vegetation growth is saturated or will be saturated in the foreseeable future…
Stevo says:
January 2, 2013 at 11:35 am
The case against AGW just gets stronger and stronger. Love it.
This does nothing to negate the case for AGW. It merely suggest that there is a noticable solar influence on global temps, maybe.
TerryS says:
January 2, 2013 at 1:00 pm
You know approximately how much CO2 enters the atmosphere from natural sources every year (about 770Gt), and what the equilibrium point is (278ppm or 2173Gt). From these two numbers you can calculate the half life: 2173 * ln(2)/770 = 2 years.
Sorry, but you are confusing the inflow with the difference between actual and equilibrium CO2 levels. It is that difference which is the driving force to remove extra CO2 out of the atmosphere. That is currently about 100 ppmv or about 210 GtC. The natural inflow is more than compensated by the natural outflow, only the difference between the two is important, which is only 4 GtC more sink than source, that is caused by the 210 GtC extra in the atmosphere. So the half life time is ~40 years…
The solar climate link is more likely in the higher latitudes since the strength of both the Earth’s and the solar induced magnetic fields changes are strongest there. Result of the combined effect is: the temperature natural variability
http://www.vukcevic.talktalk.net/GYCR.htm
Gail COmbs says:
January 2, 2013 at 1:09 pm
“…The fact we can now grow twice the wheat or corn on the same acreage is a CO2 benefit that should normally be greeted with glee instead of squirming to negate it.”
I have seen statements such as the above occur occasionally on WUWT posts over the past few years (sometimes also applied to tree growth rates), and believe it necessary to challenge the not-so-veiled implication that, were it not for increasing atmospheric CO2 concentrations, we would not be enjoying the significant increases in crop and forest production rates of the past 80-90 years.
My apologies up front if this is not what you mean to say. However, it is provable that increased per acre production rates (food crops and timber) are due more to decades of applied plant and tree breeding, and to improved crop and silvi-culture. If we take just corn as an example, the number of ears per plant, ear size, and number of kernels per ear haven’t changed much since the 1920’s. However, breeding and selection programs have drastically changed the architecture of the corn plant, such that farmers now plant at nearly 3X the density their grandfathers did.
For trees, developed western economies have had intensive applied breeding programs for nearly 60 years. In the US alone, tree breeding programs in loblolly pine and Douglas-fir are responsible for significantly increased rates of growth.
We know that CO2 is used to enhance growth in commercial greenhouses, and controlled studies have shown that higher CO2 increases tree growth. However, most of the increases of the last 80+ years are due to breeding and culture, not CO2.
Doug Proctor says:
“To date, there are no unique TSI or (as I suspect) heat redistribution or other, non-CO2 signs we can point to for the skeptical defense.
What? How about the missing hot spot? How about a inexplicable warming pause while CO2 increases? How about stratospheric cooling pause? How about ocean heat content increase pattern not matching the CO2 increases causing warming pattern? How about the warming pattern matching PDO cycles? How about warming matching solar spectral variation patterns (not just TSI, i.e.: Bond Cycles)?