Another wrong headline at WUWT about CERN and related cloud experiments

It's happened again. Anthony has written another misleading headline (archived here), this time about the cloud experiments at CERN and related research. There were three papers this week from the same group of people, discussing aspects relating to clouds with and without cosmic rays. Anthony's headline was "CERN’s CLOUD experiment results suggests industrial revolution reduced cloud cover, cosmic rays have an impact too". Well, no. The papers didn't say that the industrial revolution reduced cloud cover. I don't know how he got that idea. The papers were about ionisation, and volatile emissions from plants - both from cloud chamber experiments, plus a paper on research conducted at high altitude fairly free of anthropogenic aerosols, looking at new particle formation as a precursor to clouds.

Research from the cloud experiments at CERN

The papers are available at Nature and Science, and many of the same authors are involved in each (not exactly the same):

1. Ion-induced nucleation of pure biogenic particles - published in Nature, written by a large team led by Jasper Kirby (the same person who made some rather extravagant claims about his previous work - and more)
2. The role of low-volatility organic compounds in initial particle growth in the atmosphere - published in Nature, written by a similarly large team led by Jasmin Tröstl
3. New particle formation in the free troposphere: A question of chemistry and timing - published in Science, written by a smaller team led by Federico Bianchi

There's also an article in Science about the three papers, Earth’s climate may not warm as quickly as expected, suggest new cloud studies - by Tim Wogan.

A primer by Jeffrey Pierce at realclimate.org

I'm not sure if the conclusion suggested by the last article is warranted, however I'm not an expert on clouds. For that I recommend an article at realclimate.org, by Jeffrey Pierce, which was written in 2011: Cosmic rays and clouds: Potential mechanisms. It sets out the relevant points very clearly, describing two main mechanisms for cloud nucleation:

• the ion-aerosol clear-sky hypothesis - in which cosmic rays affect ion concentrations in the atmosphere which enhance aerosol nucleation, and 
• the ion-aerosol near-cloud hypothesis, which is to do with a charge separation between the ionosphere and the surface.

The Pierce article also talks about which aspects of these hypotheses are being addressed by the group at CERN.

More about the new cloud/aerosol papers

The gist of the work described in the three papers is probably best described in the article by Tim Wogan, although he does seem to go a bit beyond the research itself. The authors of the first paper reported that in a large cloud chamber and under atmospheric conditions without any sulfuric acid, aerosol particles could be formed from highly oxidized biogenic vapours. Further than that, they found that "ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation". I didn't see whether the size of the particles was sufficiently large for cloud nucleation. That doesn't mean a lot because I'm not familiar with the subject. Perhaps someone more knowledgeable can comment about the findings and what they might mean.

The authors of the second paper did discuss particle size. They were also reporting results of experiments in a large cloud chamber under atmospheric conditions. They were reporting "the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively". What they found was that organic vapours alone can drive nucleation. That is, that molecules like sulfur dioxide were not essential. From what I can tell, part of their experiment involved modeling, not all of it was from direct measurement in the cloud chamber. Again, I don't know if the particles were of sufficient size to form clouds. (I should add that the researchers acknowledged the importance of substances like sulphur dioxide in cloud nucleation, it's just that they were looking to see how essential it was.)

The authors of the third paper reported observations of new particle formation in the free troposphere, at a high altitude research station in Switzerland. They collected measurements over a year, including "two intensive 1-month campaigns". They also used modeling as part of their research. The last paragraph of the paper is:

Combining in situ observations and modeling results, we thus find that NPF [new particle formation] in the free troposphere depends on the availability of highly oxidized organic species, providing confirmation for NPF pathways observed in recent laboratory experiments. The availability of these highly oxidized organic species in turn depends on previous surface contact of the air mass and appropriate time to process the precursors from the boundary layer on their way up. In short, chemistry and timing play the main roles. To properly represent nucleation in the free troposphere, future atmospheric models should take these factors into account.

It was only the first of the three papers listed above that discussed the implications for climate science in the following sense:

Ion-induced nucleation of pure biogenic particles may have important consequences for pristine climates because it provides a mechanism by which nature produces particles without pollution. This could raise the baseline aerosol state of the pristine pre-industrial atmosphere and so could reduce the estimated anthropogenic radiative forcing from increased aerosol-cloud albedo over the industrial period.

Again, I don't know if that suggestion has merit or not.  It seems a bit of a stretch to me. I expect some cloud experts will discuss this - and will keep my eyes open. (Chris Colose pointed out that none of the papers mentioned climate sensitivity. Like me, he thought the claims were a bit of a stretch.)

It looks as if Anthony Watts got things back to front when he wrote that the research suggested the "industrial revolution reduced cloud cover". What the researchers were suggesting was that pre-industrial climates may have had more cloud cover, not that the cloud cover now is less than thought. Anthony even wrote that as a sub-head under his article: "Our planet’s pre-industrial climate may have been cloudier than presently thought, shows CERN’s CLOUD experiment in two papers published in Nature." So I don't know how he got his headline so wrong.

From the WUWT comments

Once again Dunning and Kruger are in evidence at WUWT. More than one person made a comment about settled science - a familiar denier catch-cry with every new paper published. (No scientist claims that all science is settled.) Bud St.Rong wrote:

May 25, 2016 at 12:23 pm
Settled Science…

george e. smith got everything topsy turvy. The research was more about how anthropogenic particles are not essential to new particle nucleation, not that they are essential.

May 25, 2016 at 4:50 pm
So it really IS true, that water droplets will not grow from zero radius requiring infinite internal excess pressure.
You’ve got to have all that soot from coal burning steam trains to grow the water droplets that make clouds.
So California’s clean air act that mandates that California air be cleaner than when the first covered wagon crossed the border into the golden state, is the real cause of global warming, by making it harder for cloud droplets to nucleate.
Talk about unintended consequences.
G

Tom Halla had a silly thought. (It's well known that plants produce organic substances that are precursors to nucleation.)

May 25, 2016 at 12:23 pm
How dreadful! Trees producing aerosols? I never would have guessed. :-) 

Tom Roche seems to think that the "midieval warm period" was post-industrial, writing:

May 25, 2016 at 12:38 pm
I thought the pre industrial era was cloudier than the midieval warm period, as judged by paintings of the periods Is this a flawed assumption and if not what caused that variability. 

tadchem picks up on something that I wondered about, too. Are the scientists correct in thinking that sulphuric acid was thought to be essential? (I don't know about the early cloud experiments he talks about.)

May 25, 2016 at 12:40 pm
“Previously it was thought that sulphuric acid – which largely arises from fossil fuels – was essential to initiate aerosol particle formation.”
What narrow-minded egotists dreamed this up?
The first synthetic clouds (Wilson – 1911) used no sulfur. Clouds were produced by ions (created by ionizing radiation!) in an atmosphere super-saturated with vapors of a substance that is normally liquid at the operating temperature. In 1936 a variation using alcohol was developed (Langsdorf).
The ‘climatiologists’ have had over a century to study this, and still don’t get it. 

Bob Shapiro has a silly thought of his own. No, "these guys" don't think it wasn't raining back when.

May 25, 2016 at 3:47 pm
If humans weren’t burning much fossil fuel a couple hundred years ago, do these guys think it wasn’t raining back then? And, does their “hitherto-unknown mechanism ” imply that they think no mechanism was around to nucleate clouds, allowing it to rain, or did they realize that, of course, it rained but now we know what one possible mechanism was?

Mark - Helsinki says something about the Director of GISS, NASA - Dr Gavin Schmidt:

May 25, 2016 at 1:11 pm
The “climate community” are “attacking like white blood cells”, Schmidt pretends to praise the study while creating doubt and essentially shooting it down.
He’s a sly one that one, always gives a long obfuscating answer to very simple questions
I have no idea as to the validity of this study and neither does Gav, he’s a modeler who doesn’t even understand statistics ffs

I don't know where Mark got that from. I'll ignore his reference to statistics. Gavin Schmidt has BA (Hons) in mathematics from Jesus College (Oxford) and a PhD in applied mathematics from University College London, and would run rings around the most mathematically astute person at WUWT (if such a being exists). Gavin Schmidt posted two tweets on the subject. One was referring people to the article by Jeffrey Pierce at realclimate.org, and the other was a suggestion that the researchers might have talked to climate modelers before jumping to conclusions about their assumptions:

@NewsfromScience Probably worth talking to an actual climate modeler before making claims about what models 'assume'.

— Gavin Schmidt (@ClimateOfGavin) May 25, 2016

The tweet above was probably a reference to the claim in Tim Wogan's article: "the result means climate modelers can't assume that the ancient past was much less cloudy simply because there was less sulfur dioxide". Or it might have been the reference in the paper in Science that "the vast majority of models use free-troposphere NPF schemes in which particle formation rates depend only on the concentration of sulfuric acid, relative humidity, and temperature". I don't know.


carl vilbrandt draws different conclusions to the researchers, and raises other questions that occurred to me. He says:

May 25, 2016 at 1:22 pm
Wow take a new finding lead by an group who believes in a coming ice age in the near past and then claim the new findings about cloud formation means / conclusion. The catastrophic climate events such as global warming of the current process of mass extinction of complex life on earth will not be so bad. This conclusion is disconnected from the new findings. Also the conclusion the earth by “organic nucleation” had more cloud cover is pure garbage. Who allowed such people who as a group did measurements at Jungfraujoch and came to a conclusion then to control CERN’s experimental cloud chamber to prove their forgone conclusions. This is as close to scientific fraud as possible. This group needs to be replaced by a different group just in the face of having made public their private conclusions as if they are supported by the new findings concerning nucleation of clouds. In fact the new findings on cloud nucleation could indicate its possible global warming could be much worse. Ouch!

I am sorely tempted to entertain these thoughts from Rud Istvan, to my amazement (given he usually writes nonsense). ristvan wrote:

May 25, 2016 at 1:23 pm
The CERN GCR impact on VOC nucleation may be new science, but the rest isn’t. Ocean algae produce dimethylsulfides, a known cloud nucleator. Coniferous boreal forests produce turpenes. Deciduous forests produce isoprenes, which is why the Great Smoky Mountains are ‘smoky’ in summer but not winter. Isoprene nucleated ‘smoke’ is actually fog. The Amazon produces both turpenes and isoprenes that nucleate early morning canopy fog. All three VOC classes get wafted aloft where they do the same thing for clouds. Been known for years.
Whether land use change means the preindustrial era was cloudier is IMO unknowable speculation. 

I hope some of you are more educated on the subject than I am, and will add some insights:)

References and further reading

Kirkby, J. et al. "Ion-induced nucleation of pure biogenic particles". Nature 533, http://dx.doi.org/10.1038/nature17953 (2016) (open access)

Tröstl, J. et al. "The role of low-volatility organic compounds in initial particle growth in the atmosphere". Nature 533, http://dx.doi.org/10.1038/nature18271 (2016) (open access)

Bianchi, F. et al. "New particle formation in the free troposphere: a question of chemistry and timing". Science 352, http://dx.doi.org/10.1126/science.aad5456 (2016)

Earth’s climate may not warm as quickly as expected, suggest new cloud studies
- article by Tim Wogan in Science, May. 25, 2016

Cosmic rays and clouds: Potential mechanisms - article by Jeffrey Pierce at realclimate.org, September 2011

What do the CERN experiments tell us about global warming? - article by thingsbreak at SkepticalScience.com

Brient, Florent and Tapio Schneider. "Constraints on climate sensitivity from space-based measurements of low-cloud reflection." Journal of Climate early release (May 2016) DOI: http://dx.doi.org/10.1175/JCLI-D-15-0897.1 (open access)


From the HotWhopper archives

• Looking at Clouds with Ulrike Lohmann at AGU14 - December 2014
• Reducing uncertainty and Jasper Kirkby of CERN's CLOUD - October 2014
• A sensitive climate workshop - and freebies from the Royal Society - March 2015, including mention of the recent paper by Bjorn Stevens on aerosols