Guest post by Alec Rawls
Miller et al. 2012 recently provided some pretty strong evidence for a solar driver of climate. “This is the first time anyone has clearly identified the specific onset of the cold times marking the start of the Little Ice Age,” said lead author Gifford Miller in January. And the dates?
LIA summer cold and ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430-1455 AD.
As you can see in the graphic above (from Usoskin 2003) these dates correspond pretty much with the midpoints of the Wolf and Spörer solar minima. (Usoskin 2007 centers Wolf at 1305 with a duration of 70 years and Spörer at 1470 with a duration of 160 years.)
Yet Miller never noted this coincidence. In fact, he tried to hide it, claiming that the onset of snow and ice growth coincided with periods of especially high volcanism (debunked both by Willis and by Wired), while dismissing the solar explanation with a misleading reference to the Maunder Minimum:
Our precisely dated records demonstrate that the expansion of ice caps after Medieval times was initiated by an abrupt and persistent snowline depression late in the 13th Century, and amplified in the mid 15th Century, coincident with episodes of repeated explosive volcanism centuries before the widely cited Maunder sunspot minimum (1645–1715 AD [Eddy, 1976]).
This is a remarkably blatant deception, acceded to by 13 co-authors plus the reviewers and editors at Geophysical Research Letters. It takes no expertise to know about the Wolf and Spörer minima. There is no physics involved, so who do these people think they are fooling?
Nobody. They just don’t think it is their job to make the case for what they regard as “the other side.” The anti-CO2 alarmists are behaving like lawyers in an adversarial legal proceeding, hiding what hurts their own case while overstating what can be fashioned in support. In the courts an adversarial system is able to elicit a measure of truth only because there is a judge to maintain rules of evidence and a hopefully unbiased jury examining the facts. These conditions do not obtain in science. The anti-CO2 alarmists are both the peer-review jury and the judge/editors, devolving into a pre-scientific ethic where acceptance is determined by power, not reason and evidence.
The lawyerly behavior of Miller et al. lead them to embrace a particular excuse for ignoring the evidence for a powerful solar driver of climate (even evidence that they themselves uncover). They don’t “need” it. But they were not the pioneers of this anti-scientific ploy. That dishonor goes to Gavin Schmidt.
Miller’s two null hypotheses, specific and general
The specific hypothesis of Miller’s paper is a feedback mechanism by which the cooling from volcanic episodes could get amplified into longer term cooling. It is “tested” via climate model. From Miller’s University of Colorado press release:
The models showed sustained cooling from volcanoes would have sent some of the expanding Arctic sea ice down along the eastern coast of Greenland until it eventually melted in the North Atlantic. Since sea ice contains almost no salt, when it melted the surface water became less dense, preventing it from mixing with deeper North Atlantic water. This weakened heat transport back to the Arctic and creating a self-sustaining feedback system on the sea ice long after the effects of the volcanic aerosols subsided.
But the real null hypothesis of the paper, the one that expresses the authors’ motivation, as revealed by blatant cover-up of their own evidence for a solar driver of climate, is more general. It appears in the last line of their abstract, which says that in order to explain the Little Ice Age, “large changes in solar irradiance are not required.”
The timings Miller found point like a neon sign to a solar explanation but he is determinedly oblivious to that evidence. He is only interested in whether there could be some other possible explanation, and as long as that null hypothesis is not absolutely falsified, he takes that as a rationale for ignoring the alternative hypothesis and the evidence for it.
What exactly is the alternative hypothesis? According to Miller’s wording, it is that the Little Ice Age was actually caused by “large changes in solar irradiance.” But nobody thinks that there have been large changes in solar irradiance. There is broad agreement that while solar magnetic activity fluctuates dramatically, solar irradiance remains almost constant. Irradiance shifts towards the UV when solar activity is high, but the change in Total Solar Irradiance is too small to bring about much decadal or century scale variation in climate.
In contrast, there is a great deal of evidence for a solar-magnetic driver of climate (second section here). This is the real alternate hypothesis, and there is at least one well developed theory for how it could occur: Henrik Svensmark’s GCR-cloud.
As a good adversarial lawyer, Miller is unwilling to betray any hint that this alternate hypothesis is even a possibility. Like Voldemart, it is the foe that “must not be named.” Thus Miller refers to the possible solar-magnetic driver of climate indirectly and incorrectly as “large changes in solar irradiance.”
Lawyerly advocacy is not science
In his role as an advocate, Miller’s fear is fully justified. A strong solar-magnetic effect on climate would be a death knell for anti-CO2 alarmism. Any late 20th century warming that can be attributed to that era’s continued high levels of solar activity reduces by the same amount the warming that can possibly be attributed to CO2, which in tern reduces the implied sensitivity of climate to CO2. Even worse, if solar-magnetic effects actually outweigh CO2 effects (my own surmise, by a wide margin) then the present danger is cooling, not warming, thanks to our now quiescent sun.
But lawyerly advocacy is not science. To only examine the evidence for non-solar explanations is to throw away information, violating the most basic scientific rationality, yet this is what the “consensus” has been doing for many years. My review of the first draft of the next IPCC report documents how “vast evidence for solar climate driver rates one oblique sentence in AR5.” AR4 listed Total Solar Irradiance (TSI) as the only solar effect on climate, as did the Third Assessment Report (scroll to TSI). “The Team” simply omits what they wish to avoid.
Miller plays this game from the get go, where his opening literature review assumes that the only solar effect is TSI:
Episodes of anomalously cold summers primarily are attributed to some combination of reductions in solar irradiance, especially the LIA Maunder sunspot minimum [Eddy, 1976], explosive volcanism, and changes in the internal modes of variability in the ocean–atmosphere system [Crowley, 2000; Wanner et al., 2011]. However, the natural radiative forcings are either weak or, in the case of explosive volcanism, shortlived [Robock, 2000], thus requiring substantial internal feedback.
Robock 2000 only addresses the volcanic issue, so Miller’s only grounds for calling solar forcing a “weak” effect is his own analysis, where he only looks at TSI (using the TSI reconstruction of Schmidt et al. 2011).
That’s a phony literature review. Miller’s repeated deceptions—hiding the Wolf and Spörer minima, referring to large solar effects as “large changes in solar irradiance” when there is no such hypothesis—can only be to hide the possible role of solar magnetic activity, but this actual object of Miller’s paper goes unmentioned in what is supposed to be a survey of the most relevant science. The literature review is a place where an adversarial approach is explicitly rejected by well established scientific standards, but the alarmists are not playing by the rules.
There is nothing wrong with Miller et al. testing their hypothesis that solar activity does not play a significant role (which they do by “setting solar radiation at a constant level in the climate models”). But when they pair this non-falsification of their pet theory with blatant misdirection about their own discovered evidence for the alternative hypothesis, that is bad. It is using the “not needed” claim as an implicit justification for the omitted variable fraud that the entire consensus is engaged in.
Gavin Schmidt is a pioneer of the “not needed” excuse for ignoring possible solar magnetic effects
Some history on this particular ploy, for anyone who is interested. Miller and his co-authors are not the first to pull the “not needed” gambit. Eleven years ago Shindell, Schmidt, Mann, Rind and Waple published a paper in Science that is remarkably similar to Miller 2012. Like Miller, Schmidt and his co-authors propose a North Atlantic mechanism for amplifying cooling effects, though the mechanism itself is quite different. The spectral shift that accompanies decreased solar activity is hypothesized to alter atmospheric ozone composition in a cooling direction, setting in motion atmospheric flows (“planet waves”) that in turn are hypothesized to drive the North Atlantic Oscillation. Their null hypothesis is the same as Miller’s: that they can account for the Little Ice Age without invoking any solar effects beyond the expected variations in solar irradiance, and their test is also the same: they run a model.
If the UV shift that goes with low solar activity can explain much of the Little Ice Age, couldn’t the UV shift from high solar activity explain a similar amount of 20th century warming? No say Shindell et al. Changes in atmospheric composition from the pre-industrial to the industrial period supposedly cause the effect of the UV shift to reverse (p. 2151):
Ozone’s reversal from a positive (preindustrial) to a negative feedback supports results showing that solar forcing has been a relatively minor contributor to late 20th-century surface warming (7, 19, 31).
Thus the CO2 explanation for recent warming is not undercut, enabling claims of future catastrophic warming to go forward. Of course Schmidt’s references “showing that solar forcing has been a relatively minor contributor to late 20th-century surface warming” only look at TSI, and his “ozone reversal” is not an empirical finding but a model result. They’ve got all the doors manned.
In 2005, this 2001 paper became the centerpiece of a public exchange between Gavin Schmidt and science fiction author Jerry Pournelle. Schmidt was vigorously insisting on the scientific integrity of himself and everyone he knew:
None, not one, of the climate scientists I meet at conferences or workshops or that I correspond with fit the stereotype you paint of catastrophists making up worries to gain grant money. Personally, I don’t think I’ve ever made a dramatic statement in papers, public speechs, grant applications or letters to the editor. Yet I still manage to keep my job and support a couple of graduate students. This is the same in every institution and university. … I do not go around being a doom sayer – but it is incumbent on scientists to explain to people what it is we think we understand, and what it is we don’t.
To explain the sober science that causes him to dismiss the solar-warming hypothesis, Schmidt invoked his 2001 paper with Shindell et al.. It shows that there is no “need” to bring in any suspicious “new physics” (Schmidt’s Voldmartian euphemism for the solar-magnetic hypothesis that must not be named):
I was a co-author of a paper in Science in 2001, that looked at whether climate models could replicate this pattern given the known physics of solar change. We found that two features were key, allowing the solar irradiance to vary more in the UV than in the visible (consistent with what is seen over the sunspot cycle), and allowing the ozone field to vary as a function of the UV and temperature in the stratosphere. With both of these effects, the model produced global cooling (as you would expect) but also a robust change to the circulation (a weakened NAO) that amplified the cooling in western Eurasia and over the mid-latitude continents. Obviously given the uncertainties in the forcing, the data that we were trying to match, and uncertainty in the model response, we can’t use this a proof that we got all of it right. However, in the absence of better data, there is no obvious need for ‘new’ or unknown physics to explain what was going on. This was just a first cut, and better models and more data are being brought to bear on the problem, so the conclusion may change in the future. As of now though, this is still the current state of thinking.
“New or unknown physics” is obviously a reference to to GCR-cloud, which Schmidt finds lacking as a theory. Fine, but that is no excuse for ignoring the ever growing mountain of evidence that there is some mechanism by which solar activity is having a much larger effect on climate than can be explained by changes in solar irradiance. I compile some of that evidence in the second section here. For the state of that evidence in 2001, the Third Assessment Report’s section 6.11.2.2 on “Cosmic rays and clouds” is well worth a look.
While AR4 and AR5 have progressively excised the evidence for solar activity as a powerful driver of global temperature, TAR actually began with several paragraphs of studies that found substantial correlations between solar activity and climate. Only then did it judge the proposed mechanisms that might account for these correlations to be too uncertain to include in their modeling.
That would be okay if they still took the discovered correlations into account in formulating their climate predictions, but of course they did not. This is the highly improper step that invalidates the IPCC’s entire enterprise. They are using theory (in particular, their dissatisfaction with Svensmark’s GCR-cloud theory) as an excuse to ignore the evidence that supports the theory, excising its known predictive power from their predictive scheme.
Evidence is supposed to trump theory, not vice versa. The IPCC is inverting the scientific method. It is literal, definitional, anti-science, and Schmidt’s “no need” excuse is simply another justification for doing the same thing. Since there is no need to invoke a strong solar driver of climate, he is going to ignore the evidence for a strong solar driver of climate, and this is what Schmidt holds up to Pournelle as an example of his integrity: the very point where he justifies the omitted variable fraud that is being perpetrated by himself and his cohorts. If only he were capable of embarrassment.
Who is actually doing a suspicious new kind of physics?
Schmidt looks askance at GCR-cloud as “new physics,” but it isn’t new in any fundamental sense. The cloud micro-physics that Svensmark, Kirkby and others are looking at is presumed to follow established particle physics models. It is a new application of current physics. What Schmidt is really suggesting with his jaundiced eye is that we should be reluctant to extrapolate our current understanding of physical principles to illuminate the biggest scientific controversy of the day.
At the same time, he and Miller and the rest of the alarmists have introduced something that really is new and problematic. They are using model runs to test their hypotheses. They are using theory to test theory, with no empirical test needed. Here Miller describes how he “tests” his theory about ocean feedbacks (page 3 of 5):
Climate modeling reveals one such possible feedback mechanism. Following Zhong et al. [2011], we tested whether abrupt LIA snowline depressions could be initiated by decadally paced explosive volcanism and maintained by subsequent sea-ice/ocean feedbacks. We completed a 550-year transient experiment (1150–1700 AD) using Community Climate System Model 3 [Collins et al., 2006] with interactive sea ice [Holland et al., 2006] at T42 x 1 resolution. Our transient simulation was branched off a 1000 AD control run, and forced solely by a reconstructed history of stratospheric volcanic aerosols and relatively weak solar irradiance changes (Figure 2b) [Gao et al., 2008].
Models are not reality, and in the above case the model is known to be wrong. Total solar effects are presumed to be “weak”? That is what the alarmists all assume but it is not what the empirical evidence says, and while they may be able to tweak their models enough to keep them from being strictly falsified by the LIA, the last decade of no significant warming has them stumped completely.
General Circulation Models are the most elaborate hypotheses ever concocted. They involve thousands of questionable steps, iterated thousands of times. To illustrate, the Shindell-Schmidt paper is good enough to provide us with a highly abridged description of the hypothetical steps that their model works through. It gives some idea of the volume and sweep of what they are theorizing (p. 2150). (If you are actually going to read this, brace yourself):
Our previous studies have demonstrated how external forcings can excite the AO/ NAO in the GISS GCM (22, 25). Briefly, the mechanism works as follows, using a shift toward the high-index AO/NAO as an example: (i) tropical and subtropical SSTs warm, leading to (ii) a warmer tropical and subtropical upper troposphere via moist convective processes. This results in (iii) an increased latitudinal temperature gradient at around 100 to 200 mbar, because these pressures are in the stratosphere at higher latitudes, and so do not feel the surface warming (26). The temperature gradient leads to (iv) enhanced lower stratospheric westerly winds, which (v) refract upward-propagating tropospheric planetary waves equatorward. This causes (vi) increased angular momentum transport to high latitudes and enhanced tropospheric westerlies, and the associated temperature and pressure changes corresponding to a high AO/NAO index. Observations support a planetary wave modulation of the AO/NAO (27, 28), and zonal wind and planetary wave propagation changes over recent decades are well reproduced in the model (22).
Reduced irradiance during the Maunder Minimum causes a shift toward the lowindex AO/NAO state via this same mechanism. During December to February, the surface in the tropics and subtropics cools by 0.4° to 0.5°C because of reduced incoming radiation and the upper stratospheric ozone increase. Cooling in the tropical and subtropical upper troposphere is even more pronounced (;0.8°C) because of cloud feedbacks, including an ;0.5% decrease in high cloud cover induced by ozone through surface effects. A similar response was seen in simulations with a finer resolution version of the GISS GCM (14). This cooling substantially reduces the latitudinal temperature gradient in the tropopause region, decreasing the zonal wind there at ;40°N. Planetary waves coming up from the surface at mid-latitudes, which are especially abundant during winter, are then deflected toward the equator less than before (equatorward Eliassen-Palm flux is reduced by 0.41 m2/s2, 12° to 35°N, 300 to 100 mbar average), instead propagating up into the stratosphere (increased vertical flux of 6.3 3 1024 m2/s2, 35° to 60°N, 100 to 5 mbar average) (29). This increases the wavedriven stratospheric residual circulation, which warms the polar lower stratosphere (up to 1°C), providing a positive feedback by further weakening the latitudinal temperature gradient. The wave propagation changes imply a reduction in northward angular momentum transport, hence a slowing down of the middle- and high-latitude westerlies and a shift toward the low AO/NAO index. Because the oceans are relatively warm during the winter owing to their large heat capacity, the diminished flow creates a cold-land/ warm-ocean surface pattern (Fig. 1).
That is a LOT of speculation. Normally it is all hidden. They just say, “we did a model run,” but this is what it actually means: ten thousand questionable steps iterated a hundred thousand times. It is fine for people to be working on these models and trying to make progress with them, but to use them to make claims about what is actually happening in the world is insane, and using them as an excuse for ignoring actual empirical evidence is worse than insane.
This really is a new kind of science, and not one that stands up to scrutiny. We are being asked to turn our world upside down on the strength of the most elaborate speculations in the history of mankind, yet Schmidt thinks it is cloud microphysics—traditional science!—that should be eschewed. All to justify the destruction of the modern world, now well underway.
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Dr. Hathaway May sunspot number ‘prediction’ is out
http://www.vukcevic.talktalk.net/SSN.htm
Lars P. says:
May 1, 2012 at 9:09 am
“Figure 3b shows that only the ACRIM composite shows irradiance increasing by ∼1 W m−2 between 1986 and 1996; if real, the solar origins of this increase are ambiguous since it is also absent in the model.”
what this is all about is really just polemic against the ACRIM data. All instruments show degradation, even TIM. The trick is to account for it correctly. Very recent work reported at the SORCE meeting last fall in Sedona acknowledges that the calibration was not done correctly. With this taken into account the simple conclusion was: “Observed data do not support a measureable TSI trend between the minima in 1996 and 2008 !” [W. Schmutz]. The 0.007 W/m2 I referred to is TIM’s precision. You are still mired in the question of absolute accuracy which is about 0.2 W/m2. BTW, I have been working with the TIM team and actually discovered the 90-day ‘keyhole’ problem and uncompensated degradation of PMOD: http://www.leif.org/research/PMOD%20TSI-SOHO%20keyhole%20effect-degradation%20over%20time.pdf
Since then the various issues have been resolved as reported at the 2011 SORCE meeting.
Alec Rawls says:
May 1, 2012 at 10:29 am
GMST is tightly coupled to the ocean mixed layer, which provides virtually all the heat capacity of the system, global mean areal heat capacity 9.4 W yr m-2 K-1 (100 m depth; fractional ocean area 0.71).
There is a lot of handwaving and half-thruths here. There is no doubt that the time scale for heating the whole ocean is thousands of years, but the time scale for the top 100 m is much shorter, less than a decade, and that is where most of the climate response on decadal and century scale comes from.
Really, it an absurd mistake for solar physicists to be making, and it needs to stop. This is Solanki’s excuse for claiming that the sun can’t be responsible for late 20th century warming
No, his claim is that before the late 20th century one could claim that there was a reasonable correlation [whether real or spurious] with no significant lag. Now this correlation has broken down showing that either the correlation was spurious to begin with, or that it was real and CO2 caused the breakdown.
David A says:
May 1, 2012 at 12:01 pm
how much does each spectrum change over a solar cycle? Leif answered my other queations, but chose not to answer what I consider to be the most important in regard to OHC.
The spectral changes are considered here: http://lasp.colorado.edu/sorce/news/2011ScienceMeeting/docs/presentations/6b_Cahalan_Sedona_9-15-2011.pdf
and are probably not what you thought [some may be in anti-phase with the solar cycle].
Alec Rawls says:
May 1, 2012 at 10:29 am
Really, it an absurd mistake for solar physicists to be making, and it needs to stop.
All the babble about lags and inertia is moot as far as I am concerned, because no matter the lag, the sun does simply not vary enough to begin with [all variation we know of on reasonable time scales is due to variations of the magnetic field]. There is a clear 11-yr cycle which should give about 0.1K variation. Some people claim to have demonstrated twice that [and that I can live with] and that without any lags: http://depts.washington.edu/amath/research/articles/Tung/journals/GRL-solar-07.pdf
You can, of course, claim that there really is a lag of precisely a large integral number of solar cycles [for example 112 cycles for a lag of 1243 years], but I would not take that seriously.
Leif writes:
Climate systems respond on MULTIPLE time scales. Solanki focused on the very visible rapid response of temperatures to short term forcings. Observing that short term response, he should expect longer term forcings to create longer term responses, such as a longer term warming in response to what in your own characterization was 300 years of mostly “high” solar activity.
Solanki’s finding on short term responses to short term forcings was a briefly lagged correlation with a magnitude of about .7. That means 30% of the time his wiggle-matching is not lining up and certainly some of that would be because there is a disjoint between what is going on with the short term wiggle-matching vs. the longer term wiggle-matchings.
Solanki does not claim, each time there is a decade where his short term wiggle matching is out of alignment, that something has broken the relationship and the sun no longer drives climate… only to turn around and say that it goes back to driving climate a decade or three later. Instead he says that the overall high correlation shows that the sun is driving climate. What justification is there for changing that now? To say only about the last disjoint episode that it implies a breaking of the long-term relationship, that is highly unscientific, especially when there is an obvious explanation in terms of the longer period forcing of the solar variable itself.
Alec Rawls says:
May 1, 2012 at 7:50 pm
Instead he says that the overall high correlation shows that the sun is driving climate. What justification is there for changing that now?
That the variables he correlated are not well determined, although, of course, there are people who say that because of the ‘overall high’ correlation, the proxies must be very good, indeed.
To say only about the last disjoint episode that it implies a breaking of the long-term relationship, that is highly unscientific
No, that is the way a spurious correlation shows itself. What looked good, turns out not to hold up. Happens all the time and is how science works by discarding theories with failed predictions.
especially when there is an obvious explanation in terms of the longer period forcing of the solar variable itself.
That works both ways, a low solar forcing would need a long time to show up in climate as there is a lot a heat stored in the oceans [by your argument].
Anyway, my main argument is the Sun has varied very little [especially magnetically] so cannot explain significant variations of climate.
Alec Rawls says:
May 1, 2012 at 7:50 pm
To say only about the last disjoint episode that it implies a breaking of the long-term relationship, that is highly unscientific
To give you an example: in the past, the solar polar field has been a good indicator of the size of the following solar cycle. Based on that [and some physical dynamo theory] I predicted that cycle 24 would be the smallest in a hundred years. If it turns out that SC24 becomes large, and this long-term relationship is broken, that implies that my theory was wrong. This is highly scientific, but I guess you would say that it is highly unscientific and that my theory is good, nevertheless. Right?
As I already noted Leif, 30% of the time Solanki’s correlation is violated, yet he has not interpreted these episodes as implying that the sun was not at these times driving climate, nor should he. The short term correlation can be obscured by longer term correlations, by ocean oscillations, by volcanic activity, and who know what. It is unscientific to treat one decade, the 1990’s, when global temperature seemed to take a step up from 1980 levels, differently from these other departures from Solanki’s observed correlation. This is especially true when solar cycle 22 seems to have been as strong as any in the record. It exhibited lower GCR than cycle 19. The idea that the hypothesis of a solar-climate driver is busted by this coincidence between especially high solar activity and a modicum of warming is quite amazing.
If you really think this episode of too much warming busts the solar warming theory (in spite of the fact that late 90’s warming was boosted by an obvious El Nino) then please apply the same standard of falsification to the CO-warming theory, which at its lowest bound predicted far more recent warming than has occurred. That, after all, is Solanki’s alternative hypothesis. He is holding that the much LESS busted solar theory should give way to the much MORE busted CO2 theory.
Personally, I don’t see how the solar theory is busted at all by a modicum of warming coincident with high solar activity. The very idea is ludicrous, and the rapid ocean equilibration assumptions that you and Solanki invoke to support it do not stand up to the least bit of scrutiny.
Now the sun has gone quiet and warming has stopped. Do you STILL think there has more recent warming than can be explained by solar activity?
Alec Rawls says:
May 1, 2012 at 9:28 pm
Now the sun has gone quiet and warming has stopped.
The sun is still shining and is still warming us [it was 78F outside today]. If it takes centuries to warm up a degree it will also take centuries to cool down a degree [unless you can produce a peer-reviewed paper that specifically goes though the physics so show why not], so we should not be able to see any cooling above the noise for a long time to come.
Do you STILL think there has more recent warming than can be explained by solar activity?
As far as I’m concerned, none of the climate variation is caused by solar activity beyond the expected 0.1K solar cycle variation.
Personally, I don’t see how the solar theory is busted at all by a modicum of warming coincident with high solar activity.
Argument from ignorance is not very fruitful. Just because you can’t see something, does not mean it can’t happen.
The very idea is ludicrous
Is a preconceived notion.
and the rapid ocean equilibration assumptions that you and Solanki invoke to support it do not stand up to the least bit of scrutiny.
Red herring. We don’t need the whole ocean to come to equilibrium, or rather, since there is no significant external forcing, there is nothing to come into equilibrium with. And don’t think I agree with Solanki. I do not. But Svensmark does [see page 19 of his paper].
As we have both recently noted, the upper ocean layer responds quickly to changes in solar forcing, so no, the expectation is not that it will take a long time for cooling to be evident. Rather, while upper ocean cooling should be evident quickly, the amount of cooling will be moderated for centuries as stored heat is drawn out of deeper ocean depths by the not-as-warm-as-they-were surface waters.
You need a peer reviewed paper to affirm such an obvious bit of reason? Bah. The peer reviewed literature is just about the last place to look for a competent analysis of anything having to do with climate science. The field is utterly debased. What decent research gets through peer review is in spite of, not because of.
Leif says, “The spectral changes are considered here: http://lasp.colorado.edu/sorce/news/2011ScienceMeeting/docs/presentations/6b_Cahalan_Sedona_9-15-2011.pdf
and are probably not what you thought [some may be in anti-phase with the solar cycle].”
Thanks Leif, that information is helpful, although not quite clear. On page three, at 250 to 325 nm I see (if I am reading this correctly) a large flux ( 7 to 10 mw/m2/nm ) in the 250 to 325 nm range. If I am reading this correctly then the tropical absobtion graph on pg 5 ?, shows this spectrum reaching the surface. Is that what you see?
Alec Rawls says:
May 1, 2012 at 10:59 pm
As we have both recently noted, the upper ocean layer responds quickly to changes in solar forcing, so no, the expectation is not that it will take a long time for cooling to be evident.
My expectation is that warming and cooling are symmetric. It takes x years to warm up and x years to cool down. Any claim of something different will have to be supported by quantitative analysis of a specific physical mechanism, no hand waving.
David A says:
May 2, 2012 at 5:55 am
If I am reading this correctly then the tropical absobtion graph on pg 5 ?, shows this spectrum reaching the surface. Is that what you see?
The absorption graph shows the heating associated with the flux and is logarithmic. Look at the scale with the “E”s. Perhaps only about a 1/1000 gets through, so in practice there is really nothing there. Note the insert at the upper right.
Leif: I didn’t suggest any asymmetry between warming and cooling. There certainly could be, but it is probably reasonable to expect that it would take heat the same amount of time to escape any particular ocean layer that it took for the heat to get in. That implies a pattern to warming or cooling.
When it has been relatively cool for a while, as at the bottom of the LIA, the deeper ocean layers have had a time to expel a pile of stored heat (or store some cold, if one prefers). Then if there is a warming force (say an increase of insolation, either from TSI variation or from GCR-cloud effects or some other source) the upper ocean layer responds quickly, allowing global surface temperatures to respond quickly, but it doesn’t get as warm as it would if deeper ocean layers were not so cold. The cold deeps draw down some of the surface warmth, storing it.
After a few hundred years of this, the deeper ocean layers will have stored a substantial amount of heat. If the warming force goes away (say the sun goes into a quiescent phase) the upper ocean layer would be expected to respond quickly, but it doesn’t cool as much as it would if deeper ocean layers were not so warm. The warm deeps draw down some of the surface cold, storing it.
Nothing asymmetrical there.
Leif Svalgaard
and
Alec Rawls
– Below 30-40 degrees latitude total heat flux is negative (downward)
– At higher latitudes total heat flux is positive (upwards)
– Change in the flux is dependant on the ocean currents and their intensity.
– Stronger currents transfer more energy pole-ward, altering the previous state in all latitude regions.
– Gulf (N. Atlantic drift), Kuroshio and the transpolar currents drive the N. Hemisphere change. .
– Circumpolar current is a principal component in the S. Hemisphere.
For all practical purposes it could be considered that the tropical and subtropical solar input is more or less constant, but the currents velocity and the heat transport are not.
Bi-decadal change in the geomagnetic field is a good proxy of the saline surface volume movements, and at the same time it correlates to a degree with the solar magnetic activity; this is not known or understood by those who would be expected to know.
Mutual correlation among these three variables is non-stationary, for number of reasons; one is the hysteresis (dependence of a system not only on its current but also on its past relevant physical state) applicable to both the water heat content and the geomagnetic variability.
http://www.vukcevic.talktalk.net/TSA.htm
It is the oceans that are principal regulators of the global temperatures on the century long time scale. The GCR and the CO2 are unlikely to have significant input on any of the above.
Alec Rawls says:
May 2, 2012 at 11:31 am
Leif: I didn’t suggest any asymmetry between warming and cooling.
Still just hand waving, no quantitative analysis, no numbers, no specific mechanism(s).
vukcevic says:
May 2, 2012 at 3:13 pm
It is the oceans that are principal regulators of the global temperatures on the century long time scale
ditto.
Vukcevic says:
If GCR is responsible for any substantial amount of cloud formation then its 10% modulation by solar activity would have a significant effect on all of the above.
Alec Rawls says:
May 2, 2012 at 5:49 pm
If GCR is responsible for any substantial amount of cloud formation then its 10% modulation by solar activity would have a significant effect on all of the above.
However, solar activity is now on par with what it was a century ago, yet the climate is not.
Leif says:
It stopped warming. It has to do that first, right?
The natural experiment of the sun going quiet is so far proceeding according to expectations from the solar theory of late 20th century warming. The lack of warming for over 10 years now suggests that solar effects are at least as large as CO2 effects. If they are the same size, temps will most likely oscillate around present temps for as long as solar activity remains low. If solar effects are larger than CO2 effects then the planet will start to cool. Either result reduces the warming possibly attributable to CO2 to non-dangerous levels.
Alec Rawls says:
May 2, 2012 at 8:31 pm
The lack of warming for over 10 years now suggests that solar effects are at least as large as CO2 effects.
I don’t know why you are so hung up on either of those. In my view, none of them are significant and you can’t play them against each other, since none of them matters.
If solar effects are larger than CO2 effects then the planet will start to cool.
And if the planet does not cool [it hasn’t yet], then you’ll conclude that it is CO2 after all?
Alec Rawls says: May 2, 2012 at 8:31 pm
The lack of warming for over 10 years now suggests that solar effects are at least as large as CO2 effects.
Not necessarily. Neither CO2 nor TSI may be responsible.
The AMO is one of the strongest ‘natural change’ components in the Northern Hemisphere, and according to the BEST natural variability report in the global land temperatures too.
Also it should be remembered that the AMO and the global temperatures are closely synchronized
http://www.vukcevic.talktalk.net/GT-AMO.gif
It can be shown that the AMO (generated in the high latitudes of the N. Atlantic) is directly related to the NAO’s northern component – Icelandic Low, with about a decade delay.
The AMO (on decadal scale) has been more or less static since late 1990s
http://www.vukcevic.talktalk.net/theAMO-NAO.htm (see the lower graph)
So question is: is the Icelandic Low driven by TSI?
I think not, as shown here:
http://www.vukcevic.talktalk.net/NorthAtlantic.gif
(note time shift in the ‘driving’ forces)
Leif: The CO2 theory is falsified on several grounds so I would not easily come around to giving it any significant credence, but the ultimate test IS prediction. It takes a long time to tell much from surface temperatures, but if ocean heat content were seen to clearly start rising then yes, I’d have to give some credibility to the CO2 theory.
Of course I don’t expect that to happen. It would fly in the face of the mountain of evidence that the primary driver of past temperature change is the sun and/or GCR (none of which depends on the second half of the 20th century exhibiting an extraordinarily high level of solar activity).
That mountain of evidence is the reason I am “hung up” on the solar explanation. As for why I am “hung up” on pointing out the falsification of the CO2 theory, you might want to poke your head out sometime and observe that a large percentage of your colleagues are declaring that the danger of CO2-driven warming necessitates the abandonment of the energy infrastructure the enables the modern world.
You dismiss the mountain of solar evidence, but the way you argue your case is often just silly, like earlier in this thread, citing Schwartz 2006 against century scale warming and cooling of the oceans when Schwartz’ very first sentence acknowledges that heat transport into and out of deeper ocean layers can easily take centuries. Or when you claim that a 300 year warming process would mean a 300 year delay in warming. I just shake my head.
I’ve spent a lot of time documenting the illogical grounds on which Solanki and others try to dismiss a solar explanation for late 20th century warming. If you’ve got something to add, I’m not finding it in your slap-dash rebuttals.
The one thing you have said that I have some sympathy with is your criticism of the correlation studies as weak and often contradictory. I’m not convinced on the contradictory part. Rapid responses to short term forcings are not at odds with longer term responses to longer term forcings. They actually imply longer term responses. Still, when studies claim to find responses with long lags, that does seem awfully weak. A long lag is not a reasonable way to represent a longer term response.
Maybe that is the source of your suggestion that 300 year warming process would cause a 300 year delay in warming. Maybe you were goofing on those correlation studies that invoke 300 year lags. But that is a small fraction of the solar-climate evidence.
Alec Rawls says:
May 3, 2012 at 9:44 am
Maybe that is the source of your suggestion that 300 year warming process would cause a 300 year delay in warming.
That source is you, when you claimed that it took three hundred years of warming to get us out of the LIA, but that a ‘quieter sun’ recently will plunge us right back into another LIA with no delay [I would think that would take another 300 years to get back down there]. But it seems that the solar angle has now become the new dogma.
Vukcevic writes: “Not necessarily. Neither CO2 nor TSI may be responsible.”
Agreed. Other things could be responsible. I only said the lack of warming for over 10 years now SUGGESTS that solar effects are at least as large as CO2 effects. It doesn’t PROVE anything.
In particular, decadal scale temperature variations seem to be dominated by ocean oscillations, which are not well understood. But the data sets for a solar-climate link are long enough to overcome this difficulty. The presence of cosmogenic isotopes allows enables lots of studies that span several millennia, which is plenty of data for average tendencies to emerge, and study after study is finding strong solar effects on climate.
Internal variability certainly could feed on itself, allowing for internally generated oscillations. As you note, there are plausible such mechanisms in the Atlantic, and Bob Tisdale theorizes the same about Pacific oscillations. I don’t dismiss those possibilities at all, but they don’t in any way undercut the extensive evidence for a solar driver of climate. They would add noise to the relationship, and even make it possible for ocean heat content to rise after the sun has gone quiet in a world where solar activity does drive climate and CO2 does not.
If ocean heat content does go up, that is one of the possibilities to look at, but I would still have to start giving some credibility to the CO2 theory. With the sun going into a quiescent phase, nature is performing the perfect experiment. We can’t ignore the results.
Well, I looked over the several 2000 yr or so records shown here.
First, I was really interested in a longer time scale, say 10,000 years. Examples, here http://jonova.s3.amazonaws.com/graphs/lappi/vostok-last-12000-years-web.gif and here http://wattsupwiththat.files.wordpress.com/2011/01/easterbrook_fig5.jpg , so for a bit, lets look at those.
The first thing, the Vostok and Greenland ice cores appear to have little relation to each other. Vostok is right near the south pole, thus, it is not a big surprise, since Vostok is pretty much as far away from anything else as you can get. My conclusion from this is that whatever is causing periods of cooling and warming, some areas will be different than others, and Vostok will be very different. Second conclusion, if you were to “average out” these two to get some kind of “global average temperature”, the Greenland temperatures would smooth out and you would not see much. Do we conclude from this that there was no MWP and no LIA? No, because this http://junkscience.com/2012/03/22/medieval-warm-period-little-ice-age-confirmed-in-antarctica/ taken offshore of Antarctica, shows evidence for both. A second conclusion is that if you carefully choose which data to include, basically cherry picking, you can get rid of little problems like LIA’s, or throw off the timing so as to make sure it does not track with anything you don’t want it to, like solar activity or CO2 or volcanoes or anything else. I therefore have to wonder where all the data came from from the 2000 yr graphs I was shown. Was there averaging out, was there cherry picking by the original graph makers, was there cherry picking when choosing which graph of temperature to compare with which graph of solar activity? Considering that many people seem to be on one side or another, for or against CO2 or cosmic rays or whatever, I have to wonder this.
Second, having seen that the MWP and LIA existed worldwide and must be taken into account and explained somehow, I look at the 10,000 yr Greenland graph above and see some definite things. First and very obvious, the LIA was at least twice as long as earlier cool periods (or more), if it was caused by cycles that tend toward coolness starting all at the same time (rather than tending to cancel each other out), wouldn’t it have only lasted as long as earlier cool periods? I mean, just how long can all the cycles ALL be cool? Second, comparing it to the solar activity, I notice that during that time frame, there was an unusual LENGTH of Grand Minimum type activity. That is one of unusual length, as well as several others of shorter length, all in that same time period, with the total length of time of very low solar activity being greater than at other times. If we assume that this quote is true It is the oceans that are principal regulators of the global temperatures on the century long time scale, well, then perhaps if solar activity levels are going to have a noticeable effect, they need to last long enough to overcome the momentum of long time scale ocean effects. Thus I suggest that when the sun has low activity, it needs to keep that up for a long period of time to have a noticeable effect on global temperature. It thus appears that the solar activity did have an affect in the LIA through sheer dogged persistence. I would guess that whether or not solar activity was the main cause of the LIA, at the very least, it appears that it was a likely cause of the sheer length of the cold in that period. Otherwise, I would have expected the length of the cold to be about the same as the earlier, shorter periods (in some cases much shorter and/or milder).
Also, since it is a reality that much of the warming of this planet is the sun warming that oceans which then warm the air, if the sun does something different, the effect will depend on which patch of ocean it shines on and what that patch is already doing. Some areas will have currents, some areas will have upwelling of deep water and the stored heat or cold there, some currents will be affected by icecaps and the like, and how fast they melt. Some things will tend to counteract each other, for instance, if cosmic rays do make for more clouds in the real world, more clouds make more shade, which can result in cooler water, which means less evaporation and less clouds, also less production of DMS which tend to aid cloud formation, thus the cosmic rays have to fight against these other forces which means that whoever is strongest will win and make either more or less clouds. And all of that may depend on time of day, latitude, currents (if any), type and amount of seal life, etc. Thus I suspect that these other forces will tend to obscure any cosmic ray (or other solar created) effects, meaning that in some areas it may have a strong effect, in others almost none, and in some effects we may not be able to see in proxies, such as no change in temperature yet fairly noticeable climate changes in some areas, such as larger temperature swings creating frosts, changes in rainfall amount or timing, and other things that could create significant effects agriculturally.
Perhaps we should not be asking, does solar activity change worldwide average temperatures, but, does solar activity (major changes in) change local climate in specific places (possibly large areas, like land in the northern hemisphere, say). Example from above, changes in Greenland (at the place they took the ice cores) significant, changes at Vostok Station near the south pole, not noticeable. We would also like to know the answer to that for specific places and at specific times in the ocean, since that is where the majority of warming or cooling will happen. Perhaps we should not let the warmists dictate the fictional idea “global average temperature”, and concentrate on the real world actual temperatures and climates, which are always different and changing. Then, we could ask, for instance, what would the effect of a longish period of low solar activity on, say, the specific place in Greenland they took these 10,000 yr ice cores from be, with it’s specific regime of ocean currents, latitude, jet streams, and everything else that effects it there. Then, we would have a better chance of seeing what effect solar activity has, and we would also be a lot better at making and matching graphs of solar activity versus temperature, being able to see, for instance, of changes in solar activity have an effect over here as compared to over there. We might thus be able to actually see something (or not see something), which we are less likely to do if we average everything out and thus have to contend with short, medium, and long scale cycles already present canceling out and muddying the data.
And a radical idea, rather than one person saying that, say, cosmic rays are the cause of, say, the LIA, or are not the cause, and insisting that no other causes be allowed to compete, could we at least admit the possibility that there may be more than one thing going on? What with ocean currents, volcanoes, CO2, ENSO, ozone, UV rays, polar vortexes, jet streams, and various other cycles of various lengths going on, and helped or apposed by forcings, feedbacks, and thermostat effects, I think that should be pretty much a given. With all that going on, if we don’t see an exact match between solar activity and climate, we should not be surprised. Even if the solar activity has a major affect, it has a lot of competition at any given moment for top dog climate wise.
Legatus says:
May 3, 2012 at 8:10 pm
Well, I looked over the several 2000 yr or so records shown here.
First, I was really interested in a longer time scale, say 10,000 years. Examples, ,,,
You make good points. And, indeed, the records are noisy and often contradictory, so it is hard to figure out what is going on. If we had a reliable mechanism we could calculate what the solar effect should be and then perhaps untangle the web, but we don’t. In addition, people are polarized and will believe anything solar if it helps defeat CO2 [or vice versa]. That leads to labels like ‘obvious’ on one side and ‘ludicrous’ on the other, none of which are helpful.