Guest post by Alec Rawls
In an interview with NewScientist magazine, Imperial College professor of atmospheric physics Joanna Haigh scoffs at the idea that late 20th century warming could have been caused by the sun:
Haigh points out that the sun actually began dimming slightly in the mid-1980s, if we take an average over its 11-year cycle, so fewer GCRs should have been deflected from Earth and more Earth-cooling clouds should have formed. “If there were some way cosmic rays could be causing global climate change, it should have started getting colder after 1985.”
What she means is that the 20th century’s persistent high level of solar activity peaked in 1985. That is the estimate developed by Mike Lockwood and Claus Fröhlich. The actual peak was later (solar cycle 22, which ended in 1996, was stronger than cycle 21 by almost every measure) but set that aside. Who could possibly think that cooling should commence when forcings are at their peak, just because the very highest peak has been passed?
Haigh’s argument against solar warming was in response to my suggestion that one new sentence in the leaked Second Order Draft of AR5 is a “game changer.” That is the sentence where the authors admit strong evidence that some substantial mechanism of solar amplification must be at work. The only solar forcing in the IPCC’s computer models is Total Solar Irradiance so if some solar forcing beyond TSI is also at work then all their model results are wrong.
No, no, no, Haigh told the NewScientist, it is “the bloggers” who have it all wrong:
They’re misunderstanding, either deliberately or otherwise, what that sentence is meant to say.
Look whose accusing people of misunderstanding. This woman thinks that warming is driven, not by the level of the temperature forcing, but by the rate of change in the level of the forcing. When a forcing goes barely past its peak (solar cycle 22 nearly identical in magnitude to cycle 21), does that really create cooling? Haigh should try it at home: put a pot of water on a full burner for a minute then turn the burner down to medium high. Does she really think the pot will stop warming, or that it will actually start to cool?
“Deliberately or otherwise,” this is an astounding misunderstanding of the very most basic physics, and Haigh is not the only consensus scientist who is making this particular “mistake.” Hers is the stock answer that pretty much every “consensus” scientists gives when asked about the solar-warming hypothesis. I have collected examples from a dozen highly regarded scientists: Lockwood, Solanki, Forster, Muscheler, Benestad, and more. Not surprisingly, it turns out that they are all making some crucial unstated assumptions.
Solar warming and ocean equilibrium
To claim that the 20th century’s high level of solar forcing would only cause warming until some particular date such as 1970, or 1980, or 1987, one must be assuming that the oceans had equilibrated by that date to the ongoing high level of forcing. That’s just the definition of equilibrium. After a step up in forcing the system will continue to warm until equilibrium is reached.
When I asked these scientists if they were making an unstated assumption that the oceans must have equilibrated by 1980 say to whatever forcing effect high 20th century solar activity was having, almost all of them answered yes, each giving their own off-the-cuff rationale for this assumption, none of which stand up to the least bit of scrutiny. Isaac Held’s two-box model of ocean equilibration is better than Mike Lockwood’s one-box model, but just move to the next simplest model, a three-box model of ocean equilibration, and any idea that longer term forcing won’t cause longer term warming collapses.
The well mixed upper ocean layer (the top 100-200 meters) does equilibrate rapidly to a change in forcing, showing a response time of less than ten years, but that isn’t the end of the story. As the top layer warms up it transfers heat to the next deeper ocean layers. If the elevated forcing persists then these next deeper layers will continue to warm on the time scale of multiple decades to multiple centuries. This warming will reduce the temperature differential between the upper and deeper layers, causing there to be less and less heat loss over time from the upper to the deeper layers, causing the upper layer to continue to warm on the time scale of multiple decades to multiple centuries.
This accords with what we actually see. Since the 50 year absence of sunspots that coincided with the bottom of the Little Ice Age, 300 years of uneven warming have coincided with an uneven rise in solar activity. Any claim that these three centuries of natural warming had to have ended by a particular 20th century date (never mind right when solar activity was at its peak), is at the very least highly speculative. To claim that we can be confident that this is what happened is borderline insane.
Or maybe it’s that other thing that Joanna Haigh insinuates about. Maybe there is an element of deliberateness to this “misunderstanding” where scads of PhD scientists all pretend that warming is driven by the rate of change of the temperature forcing, not the level of the forcing. How else to blame late 20th century warming on human activity? Some rationale has to be given for why it can’t have been caused by the high level of solar activity that was still raging. Aha, what if temperature were driven by the trend in the forcing rather than the level of the forcing? That would do it. Let’s say that one. Let’s pretend that even peak forcing will cause cooling as soon as the trend in the forcing turns down.
It’s one psycho-drama or the other: either Haigh’s insinuations about dishonesty are projection, accusing others of what she and her cohorts are actually doing, or she’s just dumber than a box of rocks.
Haigh also channels Steven Sherwood, pretending that the highlighted sentence is just about GCR-cloud
The draft report acknowledges substantial evidence for some mechanism of solar amplification and lists Henrick Svensmark’s GCR-cloud theory as an example of one possible such mechanism (7-43 of the SOD):
Many empirical relationships have been reported between GCR or cosmogenic isotope archives and some aspects of the climate system (e.g., Bond et al., 2001; Dengel et al., 2009; Ram and Stolz, 1999). The forcing from changes in total solar irradiance alone does not seem to account for these observations, implying the existence of an amplifying mechanism such as the hypothesized GCR-cloud link.
Haigh claims that the evidence about cloud formation being induced by cosmic rays points to a weak mechanism, then simply ignores the report’s admission of substantial evidence that some such mechanism must be at work:
Haigh says that if Rawls had read a bit further, he would have realised that the report goes on to largely dismiss the evidence that cosmic rays have a significant effect. “They conclude there’s very little evidence that it has any effect,” she says.
Rawls says that if Haigh had read the actual sentence itself, she would have realized that it isn’t about galactic cosmic rays, but only mentions GCR-cloud as one possible solar amplifier.
Aussie climatologist Steven Sherwood did the same thing, claiming (very prematurely) that the evidence does not support GCR-cloud as a substantial mechanism of solar amplification, then pretending away the report’s admission of clear evidence that some substantial such mechanism is at work:
He says the idea that the chapter he authored confirms a greater role for solar and other cosmic rays in global warming is “ridiculous”.
“I’m sure you could go and read those paragraphs yourself and the summary of it and see that we conclude exactly the opposite – that this cosmic ray effect that the paragraph is discussing appears to be negligible,” he told PM.
As JoNova and I blogged last weekend, this ploy inverts the scientific method, using theory (dissatisfaction with one particular theory of solar amplification) as an excuse for ignoring the evidence for some mechanism of solar amplification. Using theory to dismiss evidence is pure, definitional anti-science. Unfortunately, NewScientist gives this slick anti-scientist the last word:
“The most interesting aspect of this little event is it reveals how deeply in denial the climate deniers are,” says Steven Sherwood of the University of New South Wales in Sydney, Australia – one of the lead authors of the chapter in question. “If they can look at a short section of a report and walk away believing it says the opposite of what it actually says, and if this spin can be uncritically echoed by very influential blogs, imagine how wildly they are misinterpreting the scientific evidence.”
Sherwood and Haigh are flat lying to the public about what a simple single sentence says, pretending the admission of strong evidence for some substantial mechanism of enhanced solar forcing was never made, then trusting sympathetic reporters and editors not to call them on it. This is why the report had to be made public. After my submitted comments showed how thoroughly the new sentence undercuts the entire report it was obvious that the consensoids who run the IPCC would take the sentence right back out, and here Sherwood and Haigh are already trying to do exactly that.
Too late, anti-scientists. Your humbug is on display for the whole world to see.
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lsvalgaard says:
”Given a variation in solar output of 0.1%, the resulting temperature change is a quarter of that, i.e. 0.025% which of 288K is 0.07 degrees”
While I agree that an increase in temperature of a grey body with approximately equivalent emissivity as Earth of 0.07 degrees from 288K would necessarily result in and increase in radiant emission from that body equivalent to approximately 0.1% of total solar output, I disagree that the Stephan-Boltzman Law can be applied in reverse. The resulting temperature which is not a measure of all internal energies from the absorption of a particular amount of radiation cannot be determined in this manner. Starting from the same temperature an amount of copper and the same amount of water both absorbing the same amount of radiation will not have the same resulting temperature.
lsvalgaard says:
Pretty much no difference at all except one is used to explain away solar variation as a potential driver of 20th century temperature increase and the other is illustrating why that is nonsense.
1st 2) is saying sunspots peaked before temperatures peaked therefore it couldn’t be the sunspots or anything that correlates with sunspots since the peaks don’t coincide.
2nd 2) is saying that this same pattern happens with all drivers of temperature that occurs in cycles.
@ur momisugly lsvalgaard
I think I get the confusion, now.
Read like:
2) any solar variation that correlates to or is proxied by sunspots would have had to peak [according to the data] prior to the peak in warming [therefore couldn’t be the cause].
NOT read like:
2) any solar variation that correlates to or is proxied by sunspots would have had to peak prior to the peak in warming [for the warming to have been caused by the sunspot correlated mechanism].
Poor wording choice on my part. Although the “NOT read like” version is what my actual position is, the cause peak actually should precede the temperature peak if it’s a cause – effect relationship.
John West says:
The resulting temperature which is not a measure of all internal energies from the absorption of a particular amount of radiation cannot be determined in this manner.
To further clarify what I’m talking about:
Let’s say we have two bodies with exactly the same emissivity but different heat capacities.
If I heat both bodies to the same temperature they will emit the same amount of radiation.
But, if both absorb the same amount of radiation from the same initial temperature they will not have the same final temperature.
Therefore, we can calculate a body’s temperature from just its emissions and its emissivity, but cannot calculate the temperature a body “should” be from incoming radiation from its point of view from the emissivity and the radiation alone.
Leif:”You keep saying that, but saying it often still does not make it true.
My reason is as follows: the GCR-cloud link is specific and has some physical background, all the other ones that I know of [and which may be mentioned in the papers] are nebulous, unknown, unspecified, and mysterious ‘triggers’ or ‘amplifiers or feedbacks’ and as such cannot be seriously considered or quantified [given that we discount TSI for being too weak]. For that reason it makes sense to adopt the stance that IPCC has.”
Yes, I understand your reasoning. However, it is fallacious ie your conclusions do not follow from your premises. If the temperature effect of the 11 year solar cycle were 10 times the size it is currently, your logic would be arguing in favor of ignoring this implied amplification because we wouldn’t know what caused it. Obviously, this would cause us to miss potentially valid hypotheses.
“Science does not operate with an ‘open mind’, but with a ruthless culling of nebulous thought.”
LOL! Unfortunately, such ruthless culling of nebulousness does not appear to extend to the definition of amplification 😉
Seriously, though, without an open mind, no truly original hypothesis would ever get proposed.
“The evidence is in my opinion not good. An example is the Bond 2001 ‘evidence’ that when examined critically seems to evaporate into artifacts, dating errors, and uncertainties, with little of the original certitude left.”
And yet, the IPCC still refers to it in its discussion of these issues. Go figure.
“As I understand the two non-Bond papers, no other mechanisms are suggested. The Ram and Stoltz paper, for example, is quite specific about that ( http://www.leif.org/EOS/1999GL900199.pdf ) “In summary, our work, and that of Svensmark and Friis-Christensen (1997), seems to show that changes in cloud cover due to solar influences affects terrestrial precipitation patterns and, as a result, the aridity of the Greenland dust source areas”. no invocation of ‘amplification’ or the like. You are presuming too much.”
I still don’t think that you understand what is meant by amplification so I’ll try and lay it out in the terms of the Ram and Stoltz paper. R&S makes comparisons of the dust profiles of glacier ice(a climate proxy) and compares them to various measures of solar activity. Because the changes in the *dust profiles* track the solar activity well but are of *much greater* relative magnitude than the mere TSI changes would cause there is said to be an amplification taking place. IOW, what R&S describe is an amplification *whether or not they call it that*. Again, this is 100% consistent with the IPCC’s usage of the word.
And, for the record, just because there are two mechanisms involving GCRs doesn’t mean that those two mechanisms [are the same].
Cheers, 🙂
[Last sentence corrected as requested ~Mod]
Oops, again. The “proposed linkages” I mention above is actually from The Terrestrial Cosmic Ray Flux: Its Importance for Climate” published by those authors in 2009. I was reviewing both papers as I was typing my response and got them a bit mixed up.
lsvalgaard says:
December 21, 2012 at 7:36 am
“There has been no rise in solar activity the last 300 years.”
http://www.acrim.com/ … http://www.acrim.com/RESULTS/Earth%20Observatory/earth_obs_fig12.pdf Seem to be saying different.
And besides visible things like sunspot counts.. who exactly was measuring the energy from solar activity here on earth 100 yrs ago.. 200 yrs ago.. 300 yrs ago. You really make me crazy.
Leif
“You are running up against folks like lgl and Rawls who preach that there are enormous lags and thermal inertia involved, so no way can the ‘sun begin to cool’ the Earth yet [as some commenters put it].”
As a former viking you should know that we sometimes have these pesky highs over Russia bringing cooold air from Siberia to Europe, there’s one right now b t w. Temps at mid lat NH are controlled by the Arctic Oscillation so warm globe and cold NH winters is no contradiction.
And yes, the thermal inertia is enormous but not infinite. And the lag is not fixed, the globe will warm almost until the solar activity gets below a long-term average, which is about now.
lgl says:
“And yes, the thermal inertia is enormous but not infinite. And the lag is not fixed, the globe will warm almost until the solar activity gets below a long-term average,”
————————-
Thanks, that’s what my intuition tells me…
Leif, I read the paper you linked to above and most of the papers it references.
From the conclusions,
Although some positive evidence exists in ground-based studies, these are all from highly localized data and are suggested
to operate via global electric circuit based mechanisms: the
effects of which may depend on numerous factors and vary
greatly from one location to the next. Consequently, it is unclear
what the overall implications of these localized findings are. By
virtue of a lack of strong evidence detected from the numerous
satellite- and ground-based studies, it is clear that if a solarcloud link exists the effects are likely to be low amplitude
and could not have contributed appreciably to recent anthropogenic climate changes.
I’ll quibble with ‘highly localized data ‘. All surface measurements are ‘highly localized’.
Anyway, the Harrison, 2006 study is interesting. They found an approximate 19% decrease in cloudiness after a FDE. The largest effect was at Cambridge (UK). I’d previously thought that if we were to detect GCR effects anywhere it would be in the frequency and persistence of radiation fog, a phenomena that is completely absent in many places but is frequent in others. It happens I grew up not far from Cambridge and radiation fogs were frequent between the autumn and spring equinox.
I don’t know how significant GCRs are to the Earth’s climate energy balance. I suspect not much, but I’ll argue that they are to minimum temperatures, and thus the min/max derived surface temperature.
My hypothesis is; GCR decreases during an FDE result in decreased cloud cover (including fog, which is just low level stratus) late in the night before dawn and thus decreased temperatures shortly before dawn, and the reduced clouds persist after dawn resulting in increased temperatures shortly after dawn, including increasing the minimum temperature, but only between the autumn and spring solstice.
[snip. You have worn out your welcome here. — mod.]
John West says:
December 23, 2012 at 12:50 am
Let’s say we have two bodies with exactly the same emissivity but different heat capacities.
We do not have two bodies. The Earth is the same body before and after the change of solar radiation.
Shawnhet says:
December 23, 2012 at 1:01 am
Obviously, this would cause us to miss potentially valid hypotheses.
To say that something is ‘solar triggered’ is not a valid hypothesis, whose details can be evaluated. And the IPCC correctly does not consider something like that.
Seriously, though, without an open mind, no truly original hypothesis would ever get proposed.
The open mind is not a property of the proposer, but of the accepter. Progress is often forced upon us by the data and has nothing to do with openmindedness.
R&S makes comparisons of the dust profiles of glacier ice(a climate proxy) and compares them to various measures of solar activity.
No, they don’t. They go straight to the GCR hypothesis, based on the 22-yr cycle [alternating flat and peaked GCR records].
And, for the record, just because there are two mechanisms involving GCRs doesn’t mean that those two mechanisms [are the same].
????
Perhaps you were trying to say something different. A different mechanism cannot be said to be an amplification of another mechanism. Perhaps that is the fundamental distinction you miss.
pkatt says:
December 23, 2012 at 1:31 am
Seem to be saying different.
Nonsense
And besides visible things like sunspot counts.. who exactly was measuring the energy from solar activity here on earth 100 yrs ago.. 200 yrs ago.. 300 yrs ago. You really make me crazy.
Solar UV creates the ionosphere resulting in electric currents being generates 100 km up. These currents result in a magnetic field which can be observed at the surface. This was discovered by George Graham in 1722 and has been kept track off ever since, see: http://www.leif.org/research/H02-FRI-O1430-0550.pdf
lgl says:
December 23, 2012 at 1:48 am
the globe will warm almost until the solar activity gets below a long-term average
No, the globe will always warm as long as the Sun shines at all.
svalgaard
but you would be surprised at the cooling that has taken place after 1985 especially during the winters.
You are running up against folks like lgl and Rawls who preach that there are enormous lags and thermal inertia involved, so no way can the ‘sun begin to cool’ the Earth yet [as some commenters put it].
Playing one blogger against another Lief wastes everyone’s time. Nowhere in my post is a statement that the “sun begins to cool” the Earth nor have I even implied it .I can now see why the various bloggers on this track are so frustrated by your twisted comments. If you have problem with IGL or Rawls comments, then blog to them, not to me and answer other bloggers comments on their own merits .For a science person you seem to have very twisted sense of logic .
Philip Bradley says:
December 23, 2012 at 3:15 am
I don’t know how significant GCRs are to the Earth’s climate energy balance.
The energy flux is about three times that of the light we get from the stars.
Shawnhet says:
December 23, 2012 at 1:01 am
Obviously, this would cause us to miss potentially valid hypotheses.
As you have great difficulty with this, let me try one last time:
Let us assume that TSI gives us a 0.1 degree solar cycle effect. Let us assume for the sake of the argument that the solar wind interaction with the earth produces Joule heating of the atmosphere of 1 degree variation over the cycle, then it is incorrect to claim that the solar wind amplifies the effect of TSI. The solar wind acts in addition to TSI. The two effects have nothing to do with each other, and one is not an amplification of the other.
Philip Bradley says:
December 23, 2012 at 3:15 am
Anyway, the Harrison, 2006 study is interesting. They found an approximate 19% decrease in cloudiness after a FDE. The largest effect was at Cambridge (UK).
You might be interested in this:
http://www.vukcevic.talktalk.net//Oxbridge.htm
lsvalgaard says:
We do not have two bodies. The Earth is the same body before and after the change of solar radiation.
True that, but it’s hardly homogenous or static. But that’s not really the overall point I’m making. There seems to be the overriding belief that: Energy in = Energy out therefore we can determine the Earth’s ideal temperature from incoming radiation. This is simply not true, if it were then how’d all that energy in fossil fuels get buried in the first place? Actually, Energy out = Energy in – Work accomplished. How much work is accomplished? I have no idea what the magnitude or even the scale or how to estimate it, but it wouldn’t bowl me over if it were 0.5, 0.05, 0.005 or even 0.0005 W/m2. From splitting O2 molecules in the upper atmosphere to every photosynthetic reaction to the thermal expansion of every sunlit surface on earth, etc. the sun light coming in has a lot of work to do.
lsvalgaard says:
No, the globe will always warm as long as the Sun shines at all.
So, if the sun dropped to half output the Earth would heat up even more than it is now? LOL, no, the globe will always warm as long as the Sun shines at all relative to absolute zero but not relative to any particular or current temperature.
Lefi:”To say that something is ‘solar triggered’ is not a valid hypothesis, whose details can be evaluated.”
Sure it is. In fact, you claim to have shown Bond 2001 was inaccurate without any recourse to its proposed mechanisms at all. QED.
“The open mind is not a property of the proposer, but of the accepter. Progress is often forced upon us by the data and has nothing to do with openmindedness.”
It’s a property of both. Einstein’s theory of relativity was not forced upon us by the data, the data was there for some time and then he thought it up (because, in part, he was openminded).
“R&S makes comparisons of the dust profiles of glacier ice(a climate proxy) and compares them to various measures of solar activity.
No, they don’t. They go straight to the GCR hypothesis, based on the 22-yr cycle [alternating flat and peaked GCR records].”
Sorry my mistake here, I got this point confused with their later paper again. Regardless, I am not aware of any persistent ~22 year cycle that could possibly be causing changes in the climate.
“And, for the record, just because there are two mechanisms involving GCRs doesn’t mean that those two mechanisms [are the same].????
Perhaps you were trying to say something different. A different mechanism cannot be said to be an amplification of another mechanism. Perhaps that is the fundamental distinction you miss.”
No, it is you who is missing the fundamental point at issue which is it is the *overall effect of the sun that is amplified* not a particular mechanism. SInce the sun causes many different things to happen in many different ways, it is possible that there is more than *one* mechanism that has influence on the climate but it also driven by solar effects, as such the effect of the sun would be amplified as compared to if only a single mechanism affected the climate. Re-read the blurb from the IPCC on the top of this thread, it could not be more clear.
“Let us assume that TSI gives us a 0.1 degree solar cycle effect. Let us assume for the sake of the argument that the solar wind interaction with the earth produces Joule heating of the atmosphere of 1 degree variation over the cycle, then it is incorrect to claim that the solar wind amplifies the effect of TSI. The solar wind acts in addition to TSI. The two effects have nothing to do with each other, and one is not an amplification of the other.”
We already dealt with this exact point higher up this thread. No one is claiming that the TSI itself is amplified, what is being claimed/implied is that *solar* effects are amplified. Really, re-read the IPCC quote. This is not an arcane point and it is the core of all the issues here.
Cheers, 🙂
If there is anyone on this thread who thinks that Svalgaard will move 1 mm on this issue they are badly misinformed. flatter sun flatter earth
On that thread Paul Vaughn wrote “One of the last exchanges I ever had with Svalgaard — the one where I decided to write him off permanently as quantitatively untrustworthy — involved 2 graphs of the exact same data presented in 2 different formats. He agreed with the first and objected strongly to the second.”
Once again L.S. aligns himself with the obfuscators. It’s beginning to look non-random.
beng says:
December 22, 2012 at 9:57 am
….. Gail, are you really grouping Dr S w/some of the well-known revisionist “scientists” dealt with here? For shame…
>>>>>>>>>>>>>>>>>>>>>>>>
graph Make your own decision.
Shawnhet says:
December 23, 2012 at 7:39 am
Sure it is. In fact, you claim to have shown Bond 2001 was inaccurate without any recourse to its proposed mechanisms at all.
Nonsense, the interpretation of the data didn’t hold up, not the mechanism [as no mechanism was even mentioned].
because, in part, he was openminded
I don’t think Einstein was all that openminded [apart from the fact that you don’t really know]. He strenuously opposed Quantum Mechanics to the end, for example. I have myself made some scientific discoveries [and know personally many people who also have]. In no case was openmindedness a factor. You struggle against the discovery until you can’t ignore it any longer [either because the data or the logic become overwhelming].
Regardless, I am not aware of any persistent ~22 year cycle that could possibly be causing changes in the climate.
R&S describe in their paper such a mechanism and why they think that there is a GCR-cloud link [and no amplification of anything].
it is possible that there is more than *one* mechanism that has influence on the climate but it also driven by solar effects, as such the effect of the sun would be amplified as compared to if only a single mechanism affected the climate.
This is the critical point where you go wrong. Many papers that claim ‘amplification’ [e.g. Bond’s] speak about ‘feedback’ as well. That would be an amplification of one process, another [different] mechanism is not an amplification of the first.
No one is claiming that the TSI itself is amplified
And nobody is saying that, so your response is not relevant.
Really, re-read the IPCC quote. This is not an arcane point and it is the core of all the issues here.
The IPCC is very clear and correct on this: they refuse to discuss unspecified and unknown mechanisms. That is the take-home message that you miss. The core of the issue is whether this section is a ‘game-changer’, and it should be clear that such thoughts are just wishful thinking.
Leif Svalgaard says: December 23, 2012 at 9:32 am
In no case was openmindedness a factor. You struggle against the discovery until you can’t ignore it any longer [either because the data or the logic become overwhelming].
===============================
I know that this is true. It involves insight, but the cautious scientist guards against his fallibilities.
Leif Svalgaard says:
December 23, 2012 at 9:32 am
“The IPCC is very clear and correct on this: they refuse to discuss unspecified and unknown mechanisms.”
Gary Pearse says:
December 21, 2012 at 3:32 pm
You know, I have mentioned the Wilson Cloud chamber and the streaks of cloud created in it by GCRs, and a variety of atomic particles passing though it on about 3 or 4 occasions on WUWT without seeming to elicit any interest in this fact. Charles T. R. Wilson, Scottish physicist invented it and received the Nobel Prize in 1927. Ten years later, Carl Anderson, US physicist received the Nobel Prize for discovering that GCRs contained positrons and muons using the cloud chamber. Donald Glaser won the NP for his improvement, the bubble chamber.
After 3 nobel prizes for cloud formation by subatomic particles, surely we can lay to rest the question as to whether the mechanism is specified and known!! Lets concentrate on how large or small the effect is. It is definitely there.