An article in the New Scientist says:
But Dr. Leif Svalgaard, one of the worlds leading solar physicists and WUWT’s resident solar expert has this to say:
Solar max is a slippery concept. One can be more precise and *define* solar max for a given hemisphere as the time when the polar fields reverse in the hemisphere. The reversals usually differ by one or two years, so solar max will similarly differ. The North is undergoing reversal right now, so has reached maximum. The South is lagging, but already the polar field is rapidly decreasing, so reversal may be only a year away. Such asymmetry is very common.
Here is a link to the evolution of the polar fields as measured at WSO:
http://www.leif.org/research/WSO-Polar-Fields-since-2003.png
And here’s data all the way back to 1966, note there has not been a crossing of the polar fields yet in 2012, a typical event at solar max:
http://www.leif.org/research/Solar-Polar-Fields-1966-now.png
Here is a link to a talk on this: http://www.leif.org/research/ click
on paper 1540.
Dr. Svalgaard adds:
Solar max happens at different times for each hemisphere. In the North we are *at* max right now. For the South there is another year to go, but ‘max’ for a small cycle like 24 is a drawn out affair and will last several years. To say that max falls on a given date, e.g. Jan 3rd, 2013, at UT 04:15 is meaningless.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
kadaka (KD Knoebel) says:
October 4, 2012 at 9:19 am
So from ref 1570, where is the x1.2 correction applied?
Since Waldmeier took over in 1946 (slide 30) and the post 1945 Zurich numbers were 21% higher by sunspot area (slide 23), the second appears correct.
The exact date is hard to pin down [work in progress] as the Archives have been disappeared ( ! what else is new?), but does not matter much as 1945 was a minimum year with few spots. The different dates reflect the uncertainty on the date.
Jan P Perlwitz says: October 4, 2012 at 7:28 am
I would say those data aren’t as far away from the about 0.2 K/decade in the scenario prediction from the model simulations. Those changes in the anomalies averaged over the decades are well within the uncertainty range up to the end year 2011.
Dr. Perlwitz
De-trended North Hemisphere and the N. Atlantic SS temperatures show that the 0.2C/decade is a natural variation
http://www.vukcevic.talktalk.net/GSC1.htm
There is very little understanding of the changes due to the external causes, consequently a fudge factor is applied and the changes are attributed to the CO2.
Natural oscillations of te same order persist throughout previous 300 years as Gray and Mann have shown
http://www.vukcevic.talktalk.net/AMO-recon.htm
Jan P Perlwitz says: October 4, 2012 at 7:28 am
I would say those data aren’t as far away from the about 0.2 K/decade in the scenario prediction from the model simulations. Those changes in the anomalies averaged over the decades are well within the uncertainty range up to the end year 2011.
Dr. Perlwitz
De-trended North Hemisphere and the N. Atlantic SS temperatures show that the 0.2C/decade is a natural variation
http://www.vukcevic.talktalk.net/GSC1.htm
There is very little understanding of the changes due to the external causes, consequently a fudge factor is applied and the changes are attributed to the CO2.
Natural oscillations of same order persist throughout previous 300 years as Gray and Mann have shown
http://www.vukcevic.talktalk.net/AMO-recon.htm
Leif Svalgaard says:
October 4, 2012 at 2:17 am
Here is how the predictable, smooth outputs of a randomly driven set of coupled damped oscillators can combine to create an abrupt transition in the output SSN.
The first harmonic output is decaying slowly in accordance with its damping time constant after a period of excitation. The second is holding steady. The phases simply line up so that there is a seemingly abrupt transition in the output. But, the non-smooth output is more apparent than real. And, it is predictable given what came before.
You need to model what is actually evident in the data – multiple modes of oscillation with characteristic decay due to energy dissipation. Energy always finds a path to leak out of the system, and the rate at which it does so generally has to be determined empirically.
I’ve done the best I can to demonstrate it to you, more than you had any right to expect. If you spurn my gift, well, others will steal the march on you. But, I have other things to do now.
Leif Svalgaard says:
October 4, 2012 at 2:27 am
A good review of solar cycle prediction can be found here:
Pesnell, W. D. (2012), Solar Cycle Predictions (Invited Review), Solar Phys., The Sun 360, doi:10.1007/s11207-012-9997-5
A copy is here http://www.leif.org/EOS/Pesnell_2012.pdf
Note that the paper only discusses prediction one cycle ahead.
Bart says:
October 4, 2012 at 10:30 am
The first harmonic output is decaying slowly in accordance with its damping time constant after a period of excitation. The second is holding steady. The phases simply line up so that there is a seemingly abrupt transition in the output. But, the non-smooth output is more apparent than real. And, it is predictable given what came before.
Except that is not how the Sun operates, as I have explained to you several times.
I’ve done the best I can to demonstrate it to you, more than you had any right to expect. If you spurn my gift, well, others will steal the march on you. But, I have other things to do now.
As the Sun does not work as you assume, nothing has been demonstrated. Your effort is limited by the skill-set you have and does not apply outside of that. So your ‘gift’ really has no value and there is no ‘danger’ that some other will ‘steal the march’. It would be wonderful if someone would, but that does not seem in the cards. In the meantime we work to understand the physics of the system and will base predictions on that rather than numerology.
Mr Perlw1tz:
I notice that ‘The Sound Of Silence’ is booming in response to JJ’s question to you.
But you have attempted to draw attention from your evasion of that simple and straightforward question with a ludicrous and rambling dialogue which you aim at me at October 4, 2012 at 7:28 am.
Let us be clear. Your lies do not obscure the truth and you are delusional if you think anybody is being fooled by them except perhaps yourself.
The IPCC predicted “committed climate change” for the first two decades after year 2000 because of the increase to atmospheric GHG (notably CO2 concentrations). I cited, referenced, linked and quoted those predictions. But you say to me
I did NOT “make up” anything and you do not state anything I “made up” because you know I did not “make up” anything.
You quote and link to IPCC Box TS.9 which defines “committed climate change”. Thankyou, that confirms what I said and have repeated here. But from that you assert
No! Please do not pretend you are an idiot. As I said in the post you claim to be replying
Are you seriously claiming that the rise in atmospheric CO2 concentration measured at Mauna Loa since 1958 is “only in [my] head”?
You repeatedly made the false assertion that I had made the mistake of only drawing a “single realization” when – in fact – I had only quoted the IPCC and YOU – not me – had claimed the IPCC represented your views. I quoted you verbatim (and at length) and I rejected your offensive and untrue ranting. You now say
Bollocks!
You wrote an infantile, offensive and untrue rant. It is so silly that I copy it here so everybody can laugh at it again. Your “argument” concerning my “faulty line of reasoning” was this
And I responded to that nonsense saying
And I said
You have now replied to that saying
THAT IS YET ANOTHER REFUSAL TO ADDRESS THE FACT THAT NONE – EXCEPT PERHAPS ONE – OF THE MODELS EMULATES THE CLIMATE OF THE REAL EARTH. And it also evades JJ’s questions.
“No, I do not agree” does not constitute a logical or a scientific argument. It seems you have no idea what science and logic are.
You reinforce this indication of your lack of logical ability when you write
Say what!? That is such a load of twaddle that I need to answer each of its statements in turn.
JPP
There are no such statements by me. I haven’t said anything about “why the IPCC prediction of ‘committed warming’ has not happened.”
RSC
Absolute rubbish! You do not dispute (a) that the IPCC predicted the “committed warming” for the two decades following year 2000 and (b) that there has been no discernible warming after year 2000. And you said about “why the IPCC prediction of ‘committed warming’ has not happened” e.g.
I really do not understand why you keep stating such blatant lies as “I haven’t said anything about …”: it does you no good.
JPP
“You are just projecting your own assertion on me, according to which it hasn’t happened. If I wanted to explain “why”, I would have to accept the presumption as true first, according to which there wasn’t any “committed warming”.”
RSC
I am “projecting” nothing. You DID debate why the “committed warming” has not happened and I have quoted some of your explanation. And, therefore, you DID agree “there wasn’t any “committed warming”.”
JPP
“The evidence is lacking for the validity of the presumption, though. Results from non-robust trend analysis, the apparent “flat” temperature trend, are not evidence for it. A failure to reject the Null hypothesis that there wasn’t any change doesn’t falsify the alternative hypothesis that states there was a “committed warming” or global warming as predicted in the scenario calculations.”
RSC
You are being plain daft. You have repeatedly claimed AGW has become the “dominant climate driver at decadal and century time scales”. The “committed warming” is the AGW effect. If the AGW effect is “dominant” and exists then it cannot have been reduced to nothing by other “drivers”. THERE HAS BEEN NO DISCERNIBLE GLOBAL TEMPERATURE RISE SINCE YEAR 2000. Either the “committed warming” has not happened or it is NOT dominant: there are no other possibilities. In either case, “THE SCENARIO CALCULATIONS” ARE FALSIFIED.
JPP
“My response was about something else. It was about why your reasoning is faulty, based on which you claim that the real world temperature record contradicted the model results.”
RSC
You claim my reasoning is faulty! ROTFL.
You follow that twaddle with this
Say what!? Are you now claiming there is a discernible rise in global temperature since year 2000 or are you denying that you said “at least solar forcing has decreased in the previous decade”?
In either case I am not “projecting” anything but you are refuting your own statements.
And I am certainly NOT doing as you suggest when you write
Now that is a clear psychological projection: it attributes to me your repeated behaviours in this thread when I have done none of them.
You then go on about temperature anomalies. It seems that whenever you have lost an argument you obfuscate with irrelevance. At issue is
(1) Has there been a stasis in global temperature since year 2000?
(within measurement capability, there has been stasis according to several data sets)
And
(2) Is the present global temperature stasis different from previous similar periods?
(According to the IPCC, it is because it has more “committed warming”)
And
(3) Has the “committed warming” predicted by IPCC AR4 happened?
(It has not happened, and it now seems extremely improbable that it could be realised before year 2020).
You attempt to obfuscate those facts by comparing GISS temperature anomalies for decades prior to year 2000 and the decade after year 2000. Of course that is as relevant as the temperature of my socks before and after I donned them. The relevant fact is that there has been temperature stasis since year 2000 although the IPCC predicted “committed warming” averaged over the two decades after 2000 of 0.2K/decade: n.b. it was 0.2K/decade and NOT 0.1K/decade as you assert because the IPCC said the higher value was “committed” if CO2 emissions were within the predictions of the SRES scenarios and they have been.
So, in answer to your question
I answer:
The “committed warming” has vanished because the predicted rise of 0.2K since year 2000 has not happened. The anomalies you quote are as relevant as the temperature of my socks.
Now, having tried your diversion which I have answered, will you answer JJ’s questions?
Richard
From Jan P Perlwitz on October 4, 2012 at 7:28 am:
I am certain anyone reading that would be quite impressed with the effort you exerted to convert them to Kelvin from the original GISS presentation as degrees Celsius, especially as Kelvin is so much more scientifically authoritative thus its use would befit such as yourself.
Let’s see, GISTEMP LOTI, three decade ranges, 1981-1990, 1991-2000, and 2001-2010, all inclusive.
Done.
http://www.woodfortrees.org/plot/gistemp/from:1981/to:1991/plot/gistemp/from:1981/to:1991/trend/plot/gistemp/from:1991/to:2001/plot/gistemp/from:1991/to:2001/trend/plot/gistemp/from:2001/to:2011/plot/gistemp/from:2001/to:2011/trend
Note in WFT notation the “from” year is included, the “to” year is excluded.
1991-2000 has the greatest rate of warming, expected as it includes the 1997-98 Super El Nino.
But it is clearly seen the 2001-2010 rate of warming is far reduced, even lower that 1981-1990. All the way down to 0.045K/decade. Looks rather stalled to me.
And the models are saying 0.2K/decade, 4.4 times that rate?
Let’s shift one year, look at 2002-2011. Uh-oh! Now there is cooling, the temperatures are dropping 0.017K/decade!
Now let’s look at trends for the decades since the Super El Nino, 1999-2008, 2000-2009, 2001-2010, and 2002-2011:
http://www.woodfortrees.org/plot/gistemp/from:1999/to:2009/trend/plot/gistemp/from:2000/to:2010/trend/plot/gistemp/from:2001/to:2011/trend/plot/gistemp/from:2002/to:2012/trend
The rates of warming are clearly going down, the warming is decelerating, with the last rate negative.
Heck, let’s look at ten straight decade trends, from 1993-2002 to 2002-2011:
(Long link)
The evidence is clear. Global warming hasn’t just hit a lull, it decelerated, with the last rate negative. Global warming has reversed. While the atmospheric concentrations of CO₂ and CH₄ continue their merry rise.
It’ll take some more years to be certain, with the decade rates staying negative, and likely increasingly negative. But offhand it looks like Anthropogenic global warming has stopped being a problem. Non-anthropogenic global cooling, now that may be becoming something worth worrying about.
“I’ve done the best I can to demonstrate it to you, more than you had any right to expect. If you spurn my gift, well, others will steal the march on you. But, I have other things to do now.”
So spoke Gizbart the Orc to Gandalf, before turning on his heel and commencing a firm stride as far from the coming battle at Mordor as he could muster, leaving the party to wonder amongst themselves what greater task the argumentative interloper could possibly have set for himself.
– unused Lord of the Rings concept by JRR Tolkien, recovered from a bucket by the fireplace before being burnt, used as wrapping paper for a broken child’s toy that was put away.
JanP, richardsourtney, etc
Sometimes a picture is worth a thousand words. Here’s the picture:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-10-4.html
It is very clear that the orange line represents the “committed” temp increase which is based on no additional CO2 from 2000 forward. Clearly, actual temps from 2000 until now are lower than the “committed” projection, while actual CO2 levels are higher than 2000 levels.
davidmhoffer:
As you say in your post at October 4, 2012 at 3:40 pm
Yes. Indeed so. But that is not in dispute.
In his post at October 4, 2012 at 7:28 am, Mr Perlw1tz pretended that temperature data from BEFORE 2000 provides an indication concerning the reality of “committed” temperature increase which the IPCC predicted for AFTER 2000. As I said, the temperature data he presented is as relevant to the prediction for after 2000 as the temperature of my socks (and I am certain he knows that).
Importantly, he presented the irrelevant data as part of his attempt to avoid – and to distract from – the straightforward question from JJ. He really doesn’t want to discuss the faults in the models, and his desire to avoid that discussion is very understandable when he is a climate modeler and the climate models are rubbish: if the models were any good then he would want to take every opportunity to proclaim their abilities and to discuss their limitations.
Richard
Bart says:
October 3, 2012 at 7:44 pm
“I do not know precisely how well I could predict the SSN after a given number of cycles. But, I know that I can predict them, and I know that I can estimate accurate error bounds for the predictions, and that in itself is something of considerable value.”
There is a solid reason why it is impossible to use previous sunspot data or solar proxy records to extract some sort of recurring pattern to predict future sunspot cycle strength or grand minima. Put simply the pattern never repeats exactly although there is a rough underlying trend that lures those into a false trap. I tried to explain this phenomenon to Willis but he was too pig headed to learn. Vuk’s equation has missing components otherwise he is on the right track.
Once you understand how the pseudo pattern repeats everything becomes clear and that trying to use mathematical tools is fruitless. Contact me on my blog if you wish to know more.
richardscourtney;
I started wondering what CO2 concentration the B1 scenario in the graph I linked to would be in 2012. To my surprise, the various scenarios described in the SRES don’t seem to say anything at all about Co2 concentrations. They are all in gigatons of carbon per year. Am I missing something here? Is there not some expression of the various scenarios in terms of the expected CO2 levels? Forcing from CO2 has to be calculated from concentration levels which cannot be directly extrapolated from the amount of carbon we burn since the resulting CO2 doesn’t all stay in the atmosphere, some of it gets taken up by the biosphere, oceans, etc. Where’s the conversion from gigatons per year to ppm in the atmosphere?
davidmhoffer:
At October 4, 2012 at 7:00 pm you ask me:
The basic procedure was initially described in the First IPCC WG1 Report and is Chapter 2 titled ‘Radiative Forcing of Climate’.
The SRES scenarios are daft (I have published on this) but, for this answer, I take them as read.
The anthropogenic emissions of GHGs are estimated and their contributions to atmospheric concentration are calculated; e.g. the (ridiculous) Bern Model is used to determine how much the CO2 increases in the air as a result of an annual anthropogenic emission of CO2. Thus, an estimate is obtained for the anthropogenic increase to each GHG in the air.
The “CO2 equivalence” of each GHG (e.g. CH4) in the air is calculated. Subsequent IPCC Reports have endorsed the method but have amended values of “CO2 equivalence”. The procedure is as follows.
1.
The “CO2 equivalence” of a GHG is the amount of CO2 that would provide the same change to radiative forcing as the GHG if it were added to the air.
2.
All the calculated “CO2 equivalence” values are added to obtain a total “CO2 equivalence” of the GHG in the air for each year.
3.
The total “CO2 equivalence” is converted to gigatonnes of carbon (GtC) by assuming it is actually CO2 and the volume of the atmosphere is a constant (1.5 ppmv of CO2 in the air is equivalent to about 3 GtC in the air).
I hope this succinct answer is clear.
Richard
Geoff Sharp says:
October 4, 2012 at 5:48 pm
Geoff, please post any links where you discuss what you have uncovered. It could be helpful an enlightening.
The pattern in my simulation never repeats exactly, either, because of the disturbances driving the oscillations. The question is, how rapidly does the disturbance modulate the pattern in amplitude and phase, and how quickly will a propagated oscillation diverge from reality? These questions can be answered, and the indications are that several cycles likely can reasonably be projected forward, because the contributing harmonics are reasonably smooth, even when the resulting measurement can be highly variable.
Leif is quite wrong about the character of this time series. The “restoring force” he demands is embedded within the Laplacian of the governing equations in his model. It astounds me that he could have worked with these dynamics for so long, and yet not appreciate what the terms in his equations represent. No doubt, pointing it out will only occasion another nasty shouting match, so to save time, take it as read that he will disparage my capabilities once again, and insist that he has a lock on the one and only true way of viewing things, and I am a fool. Meh.
This is not to say that I have the one and only true way of viewing things. A simple, reduced complexity model such as I have suggested can be used to formulate a linear Kalman Filter, which is generally much more robust than a filter which tries to add in noonlinear complexity which is swamped by the disturbances, and so is not likely to help much, if at all, and may even contribute to more rapid divergence of the prediction. But, if additional terms can be added to the model which strongly influence particular behavior above the S/N ratio, this would help improve things. Also, performing a system identification to determine any limitation of the bandwidth, or particular character of the disturbances, would also help. Taking it all into account, and determining steps to improve the estimation, is a monumental task which could keep several analysts continually employed over many years, which is why I likened the full task to building a 747 in my back yard to davidmhoffer.
You guys reading this can disparage me all you like. You can hate me for an insensitive lout. But, I have actually successfully completed projects like this, and seen the fruits of my labors, so it really doesn’t matter to me. As of right now, there have been 29 views to my latest chart. There have been over 400 to the other plots I have put up on this topic. Hopefully, some of those views are from people who will take the ball and run it to the goal line. That is all that really matters to me. I hope the things I have pointed out will be of benefit to someone. For that special someone, or someones, I will repeat some key items:
1) use a multi-mode model – the existence of at least two major harmonics is revealed in the PSD. The way these modes interfere with one another is key to reproducing large swings in the output, as shown here, while maintaining smooth, predictable underlying processes
2) run the filter backwards and then forwards over the data to prime the prediction phase. Consult a text on Kalman Filtering for constructing the backward filter formulation. You want to get the best estimates of the initial states possible for initiating the prediction forward.
3) perform identification analysis to obtain the best estimates for model parameters – the rate of energy dissipation which leads to damping ratios is key to being able to produce robust and reliable predictions.
Bart says:
October 5, 2012 at 7:51 am
Geoff Sharp says:
October 4, 2012 at 5:48 pm
The “restoring force” he demands is embedded within the Laplacian of the governing equations in his model.
Still that is not how the Sun works.
You guys reading this can disparage me all you like.
You seem not to be able to draw the distinction between disparaging a person [as you do all the time] and pointing out that what that person says is wrong [as I do].
The bottom line is that people have already trying what you suggest and have found that the approach doesn’t work. The way forward is the measure in real time what the actual internal flows are in the Sun [we can do that now] and then go from there. Numerology dressed up in whatever clothes you think are pretty doesn’t work.
JJ wrote in
http://wattsupwiththat.com/2012/09/28/dr-leif-svalgaard-on-the-new-scientist-solar-max-story/#comment-1099290
Well, the forcing from the difference between TSI at solar maximum and solar minimum equivalent to an amount of greenhouse gas forcing that is added over 10 to 15 years is not so much over a time period of multiple decades and a century, considering that greenhouse gases add this amount of forcing every 10 to 15 years, currently, whereas, assuming solar activity stayed at the minimum it would be only a one-time subtraction altogether, counteracting the greenhouse gas forcing. Averaged over the whole solar cycle, let’s say cycle 22 as baseline, the decrease in solar forcing wouldn’t be equal the difference between maximum and minimum, anyway. Instead, it would be the difference between the average TSI over the whole cycle and minimum TSI.
As for the model simulations. State-of-the-art Earth system models use the historic variability of the solar forcing as input to drive model climate together with the other climate drivers. However, for future scenarios the solar cycle was prescribed constant for CMIP3. The same for CMIP5. I guess the problem is that no one really knows how the solar cycle is going to develop over future decades and centuries, and when those experiments were designed there wasn’t as much scientific hypothesis out there about a period of “hibernation” of the sun over the next decades.
I would like to do some future scenario calculations with the assumption of solar variability is going into a state like the Maunder Minimum to test the sensitivity of these scenarios to such a change in solar variability. However, currently I’m working on different projects, which have exhausted my time budget.
I find the prospect of the sun going into a Maunder minimum like state very exciting. I really hope it’s going to happen. It will be sort of the ultimate test for the question which one of the two forcing dominates nowadays, anthropogenic greenhouse gas forcing or solar forcing. I suppose you can guess what I think, which one is the more important one for present-day global climate.
davidmhoffer wrote in
http://wattsupwiththat.com/2012/09/28/dr-leif-svalgaard-on-the-new-scientist-solar-max-story/#comment-1101272
The curves you see in the graphic are low-pass filtered model output. It is not scientifically sound to compare low-pass filtered model output, where short-term unforced variability on interannual time scales has been largely removed, with unfiltered data from observations that have all the short-term unforced variability present. This unforced variability makes the temperature record from the real world wobble, with quite large amplitude, around the long-term trend. The proper comparison to the model output is done by using also a low-pass filtered observed temperature record where the short-term variability is equally strongly damped like for the model output. This is how I have done it, when I used the decadal averages of the observed temperature record in one of my previous comments. Doing this shows that the longer-term trend of the low-pass filtered observed temperature is quite well in agreement with the model projections.
JanP;
The curves you see in the graphic are low-pass filtered model output. It is not scientifically sound to compare
>>>>>>>>>>>>>>>>>>>>>>
So, you are admitting that the science as presented in the IPCC report is misleading in this case?
davidmhoffer wrote in
http://wattsupwiththat.com/2012/09/28/dr-leif-svalgaard-on-the-new-scientist-solar-max-story/#comment-1101916
What? No, I am not. Why would you say that?
JanP
What? No, I am not. Why would you say that?
>>>>>>>>>>>>>>>>
Jan, seriously? Read the string again.
Jan P Perlwitz:
I read your musings at October 5, 2012 at 8:31 am . I would now be interested to read an answer from you to JJ’s questions which that post quoted. Please provide answers.
Richard
Oh! It has already been retrieved. Thankyou Mods.
Richard
Jan P Perlwitz says:
October 5, 2012 at 8:15 am
I find the prospect of the sun going into a Maunder minimum like state very exciting. I really hope it’s going to happen. It will be sort of the ultimate test for the question which one of the two forcing dominates nowadays, anthropogenic greenhouse gas forcing or solar forcing.
Unfortunately, it may very well be that this will not be the ‘ultimate’ test:
http://www.agu.org/pubs/crossref/2011/2011GL046658.shtml
“Therefore, the best estimate of magnetic activity, and presumably TSI, for the least-active Maunder Minimum phases appears to be provided by direct measurement in 2008–2009. The implied marginally significant decrease in TSI during the least active phases of the Maunder Minimum by 140 to 360 ppm relative to 1996 suggests that drivers other than TSI dominate Earth’s long-term climate change.”
Leif Svalgaard:
I write to support your opinion stated at October 5, 2012 at 12:10 pm.
The assumption that a ‘Maunder Minimum’ would “be sort of the ultimate test for the question which one of the two forcing dominates nowadays, anthropogenic greenhouse gas forcing or solar forcing” presupposes that one of these two forcings “dominates”.
In reality it is quite possible that internal variability of the system may dominate both anthropogenic greenhouse gas forcing and solar forcing. Several people – including me – have been pointing out this possibility since the early 1990s.
Notably Richard Lindzen has been consistently explaining the matter. His first publication concerning the possibility of which I am aware was in 1997. Much more recently he has published an explanation at
http://www.glebedigital.co.uk/blog/?p=1450
His explanation at that link says
Richard