WUWT is taking a break to indulge in ozone hole denial

Over at Anthony Watts' anti-science blog, they are taking a break from rejecting climate science and returning to ozone hole denial.  It was prompted by a tweet from Andrew Dessler:

"You guys cried wolf about ozone depletion." "Actually, we saved your lives." http://t.co/8LRrUDb3Yf
— Andrew Dessler (@AndrewDessler) March 8, 2014

Andrew Dessler is a renowned climate scientist and professor from Texas A&M University with a PhD from Harvard, an impressive publication history and a decent entry in Wikipedia.  Anthony Watts is a blogger from Chico with an err... umm... a publication history and errr... umm... an entry in rationalwiki.  (Actually Anthony has a Wiki entry too :D)

Of course the fact that Anthony's just a denier blogger has never stopped him from taking a swipe at proper scientists.  In fact, it's probably why he takes a swipe.  After various odd jobs on school boards and announcing weather on tv, he's finally found success at last, of a sort. He'll never make it in the scientific world but by making a career of scoffing at science he's managed to become a minor celebrity among the scientific illiterati.  The dregs of society.  The Luddites.

Claiming a question

Anthony spun Andrew Dessler's tweet off into one of his "claim" headlines which, in this case, makes no sense, because it's not a claim, it's a question:

Claim: What would have happened to the ozone layer if chlorofluorocarbons (CFCs) had not been regulated?

A five-year-new paper!

Anthony wrote, immediately under his headline:

A new modeling based paper in Atmospheric Chemistry and Physics takes on that question directly.

A "new" paper? A modeling based paper?  Let's see.  Anthony provided a link to this paper, published five years ago to the month - in March 2009.  Talk about taking a long time to catch up to the science!  Of course his "modeling based" was a dog-whistle to his followers who haven't twigged that models are behind the knowledge revolution of the past century! (Think DNA, space exploration, particle physics, flight, finance etc etc etc)

Well, what would have happened?

The Newman et al paper was addressing the second of two important questions.  I'll let the authors explain (my bold italics):

The regulation of ODSs [ozone depleting substances] was based upon the ozone assessments that presented the consensus of the science community. The regulation presupposed that a lack of action would lead to severe ozone depletion with consequent severe increases of solar UV radiation levels at the Earth’s surface. Because of the successful regulation of ODSs, ozone science has now entered into the accountability phase. There are two relevant questions in this phase. First, are ODS levels decreasing and ozone increasing as expected because of the Montreal Protocol regulations? Second, what would have happened to the atmosphere if no actions had been taken? That is to say, what kind of world was avoided? It is this latter question that is the focus of the present study.

You can read the paper to get the full picture.  Here is one of their charts that shows what the world avoided in regard to depletion of stratospheric ozone:

Fig 2: Annual average global ozone for the WORLD AVOIDED (solid black), reference future (red), fixed chlorine (green), and reference past (blue) simulations. The curves are smoothed with a Gaussian filter with a half-amplitude response of 20 years, except for the WORLD AVOIDED, which is unsmoothed. The dashed line shows the 2-D coupled model simulation of the “world avoided”. The thin horizontal lines indicate the 220-DU level (the level usually indicating the areal extent of the Antarctic ozone hole) and the 310-DU level (the 1980 global value). The inset shows the WORLD AVOIDED total ozone plotted against global annually averaged EESC at 4.5 hPa from Fig. 1. Source: Newman et al (2009)

It was Mario Molina and F Sherwood Rowland who first alerted the scientific community and the world to the dangers of ozone depletion.  You can get a copy of the 1974 paper in Nature by Molina and Rowland 1974 here.

From Ozone Acceptance to Ozone Denial

I decided to see what Anthony has written about ozone in the past.  It's a bit of a mix.  At one stage in September 2009 he acted as if he knew something about the subject and accepted the science, but it soon becomes obvious that all he did was copy and paste press releases, as usual.

For example, that article in September 2009 was preceded by one of his classic backflips here, where he got pulled up for the title of one of his articles: "Galactic Cosmic Rays May Be Responsible For The Antarctic Ozone Hole".  That was back in March 2009, just a few days after the publication of the Newman & co paper.  I did a quick scan to find out what happened to that notion, which was put forward by Q.-B. Lu of the University of Waterloo (full paper here).  Seems to me that Q.-B. Lu is about the only one who favours Lu's idea, with other researchers showing why it ain't so, including Jens-Uwe Grooß and Rolf Müller.

TonyB has been wondering about ozone since 2009 (at least)

Interestingly, Tonyb has written almost identical comments to Anthony's September 2009 article and his March 2009 article and his March 2014 article.  This is from 2014:

how do we know if there hasn't always been an ozone hole prior to our ability to measure it from the late 1950′s?

First of all, back in the 1950s there wasn't an ozone "hole" over Antarctica of the type there is today.  It was first reported in the 1980s (eg Farman et al 1985).  Secondly, the chemistry is now quite well understood as discussed by Molina and Rowland (1974), Solomon et al (1986), Drew Shindell and co (1998) - who elaborate on the importance of temperature - and others.  For a simple explanation, the EPA account is not bad. Wikipedia has a longer description and isn't too technical.

(TonyB is, I believe, the same Tony Brown who thinks that England climate is back to what it was in the 1730s!)



Anyway, as you'd expect, Anthony Watts flip flops between proper scientific articles and ones from "CFC deniers" but always with the theme "it's not bad".  Deniers need nothing more than to be reassured.

From the WUWT comments

I think the crowd at WUWT are quite pleased to protest something other than global warming and the greenhouse effect, although some of them probably aren't too clear on the difference between them.

Dodgy Geezer is a fake sceptic who "recalls" stuff without citing anything (you'd probably not need all your fingers, let alone your toes to count the number of fake sceptics who cite scientific papers).  He says:

March 8, 2014 at 10:15 am
I do have a strong suspicion about the whole CFCs issue.
As I recall, the chemical was banned on the grounds that lab tests and models showed that it could damage ozone – there were few actual observations in the field, and those which were done were inconclusive.

I also believe that the banning also came at a very convenient time for DuPont, which would otherwise have lost the patent on a very lucrative chemical, and seen other companies undercut it heavily.

I never gave the issue a lot of thought before, but it is so similar to the AGW exercise, that you have to wonder…

sunshinehours1 says:

March 8, 2014 at 10:20 am
They took CFCs out of my asthma inhaler and replaced it with something less effective. I won’t forgive them for that. 

Thing is, the CFC's in asthma inhalers were purely a propellant like they were in all spray cans.  They didn't have any medicinal properties.  In regard to physical properties, this article suggests their replacement has some advantages.  sunshinehours1 is suffering a kind of reverse placebo effect.


Perennially puzzled Bob Tisdale, who relies on models for much of his "analysis" (eg he uses ERSST for his sea surface temperature "analysis") says:

March 8, 2014 at 10:23 am
Another modeling exercise….yawn.

There are quite a few people who think it's physically impossible for CFCs to reach the stratosphere because they are too heavy.  (The EPA explains why they are wrong.) For example:

george e. conant says:

March 8, 2014 at 10:25 am
cfc’s are too heavy and can not rise up, they sink rapidly, thump. 

Dennis Hand says (extract):

March 8, 2014 at 11:36 am
The basic laws of physics say that lighter materials will float above heavier materials. So, if the atomic weight of a free Nitrogen molecule (N2) is 14 amu’s and that of a free Oxygen molecule (O2) is 16 amu’s and that of a free CFC-12 molecule is 64 amu’s, 4.57 time heavier than a Nitrogen molecule and 4 time heavier than an Oxygen molecule, the question to ask is how did something so heavy, comparatively, get up to the ozone layer, between 50,000 and 115,000 feet above us? 

Keitho says:

March 8, 2014 at 11:41 am
I still don’t understand the mechanism for fairly heavy CFC molecules to get from the Northern hemisphere to the South. What propelled them? 

cba mixes conspiracy with "too heavy" and says (excerpt):

March 8, 2014 at 1:31 pm
The ozone hole was discovered during IGY (International Geophysical Year) back in 1957 – before there was substantial amounts of freon. I was told this back in 1974 – by someone who participated in IGY. The whole scam is the same old thing. Sheep going blind due to uV – a pink eye epidemic. CFCs escaping from airconditioners and refrigerators in the nothern hemisphere sneaking down to the antarctic where these rather heavy molecules were magically lifted up against gravity to go up into the stratosphere where they were disassociated into chlorine atoms while ocean spray chlorine ions were washed out of the atmosphere by rain just like the chlorine atoms injected into the stratosphere by an active volcano down there. 

Ignorant Pittzer thinks he's being funny when he says:

March 8, 2014 at 1:39 pm
CFCs are amazing molecules. They are emitted in an ozone rich environment, and despite being highly reactive, they eschew the “dirty” ozone from our tail pipes, defy gravity, and then fly up above the troposphere to munch on the much tastier ozone deposited by lightning in our upper atmosphere. This molecule exhibits preference and mobility. Could it be a new life form?

It's illuminating the number of WUWT-ers who "always wonder" without bothering to find out "why".  It's not as if the information isn't widely available.  For example, James the Elder says:

March 8, 2014 at 6:52 pm
george e. conant says: March 8, 2014 at 10:25 am cfc’s are too heavy and can not rise up, they sink rapidly, thump.

Always wondered why CFCs got that high to destroy ozone, but couldn’t seem to accomplish the same thing at ground level. 

---

Farman, J. C., B. G. Gardiner, and J. D. Shanklin. 1985. "Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction." Nature 315: 207-10

Lu, Q-B. "Correlation between cosmic rays and ozone depletion." Physical review letters 102, no. 11 (2009): 118501.

Molina, Mario J., and F. Sherwood Rowland. "Stratospheric sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone." Nature 249, no. 5460 (1974): 810-12.

Newman, Paul A., L. D. Oman, A. R. Douglass, E. L. Fleming, S. M. Frith, M. M. Hurwitz, S. R. Kawa et al. "What would have happened to the ozone layer if chlorofluorocarbons (CFCs) had not been regulated?." Atmospheric Chemistry and Physics 9, no. 6 (2009): 2113-2128.

Shindell, Drew T., David Rind, and Patrick Lonergan. "Increased polar stratospheric ozone losses and delayed eventual recovery owing to increasing greenhouse-gas concentrations." Nature 392, no. 6676 (1998): 589-592.

Solomon, Susan, Rolando R. Garcia, F. Sherwood Rowland, and Donald J. Wuebbles. "On the depletion of Antarctic ozone." Nature 321, no. 6072 (1986): 755-758.

Solomon, Susan. "Progress towards a quantitative understanding of Antarctic ozone depletion." Nature 347 (1990): 347-354.

Gavin Schmidt & Co have been reconciling climate models and surface temperature observations

Gavin A. Schmidt, Drew T. Shindell & Kostas Tsigaridis have a new article in Nature Geoscience (open access).  What they've done is estimate the impact of actual measures of solar, volcanoes and ENSO on a CMIP5 ensemble.  They found that this reduced the recent difference between models and observations a whole lot.

What they found in particular was the the models most likely overestimated the cooling from the Pinatubo eruption in the 1990s, making the models too cool and, when observed solar radiation, volcanic eruptions and ENSO were factored, in the models are pretty close to observations.

Here is the figure from the paper. Click to enlarge it.

Figure 1: Updated external influences on climate and their impact on the CMIP5 model runs.
a, The latest reconstructions of optical depth for volcanic aerosols9, 10 from the Mount Pinatubo eruption in 1991 suggest that the cooling effect of the eruption (1991–1993) was overestimated in the CMIP5 runs, making the simulated temperatures too cool. From about 1998 onwards, however, the cooling effects of solar activity (red), human-made tropospheric aerosols (green) and volcanic eruptions (pink) were all underestimated. WMGHG, well-mixed greenhouse gases.
b, Global mean surface temperature anomalies, with respect to 1980–1999, in the CMIP5 ensemble (mean: solid blue line; pale blue shading: 5–95% spread of simulations) on average exceeded two independent reconstructions from observations (GISTEMP Land–Ocean Temperature Index (LOTI)6, solid red; HadCRUT4 with spatial infilling7, dashed red) from about 1998. Adjusting for the phase of ENSO by regressing the observed temperature against the ENSO index11 adds interannual variability to the CMIP5 ensemble mean (dashed blue), and adjusting for updated external influences as in a further reduces the discrepancy between model and data from 1998 (black). The adjusted ensemble spread (dashed grey) clearly shows the decadal impact of the updated drivers. As an aside, we note that although it is convenient to use the CMIP5 ensemble to assess expected spreads in possible trends, the ensemble is not a true probabilistic sample.

It's going to get hotter

The authors conclude the following, which won't come as news (or welcome news) to HotWhopper readers (my bold):

We conclude that use of the latest information on external influences on the climate system and adjusting for internal variability associated with ENSO can almost completely reconcile the trends in global mean surface temperature in CMIP5 models and observations. Nevertheless, attributing climate trends over relatively short periods, such as 10 to 15 years, will always be problematic, and it is inherently unsatisfying to find model–data agreement only with the benefit of hindsight. We see no indication, however, that transient climate response is systematically overestimated in the CMIP5 climate models as has been speculated, or that decadal variability across the ensemble of models is systematically underestimated, although at least some individual models probably fall short in this respect.

Most importantly, our analysis implies that significant warming trends are likely to resume, because the dominant long-term warming effect of well-mixed greenhouse gases continues to rise. Asian pollution levels are likely to stabilize and perhaps decrease, although lower solar activity may persist and volcanic eruptions are unpredictable. ENSO will eventually move back into a positive phase and the simultaneous coincidence of multiple cooling effects will cease. Further warming is very likely to be the result. 

Anthony Watts hasn't picked up on this paper yet, but I expect he will sooner or later.

For the record, this is a link to the March 2014 special issue of Nature Geoscience "Recent slowdown in global warming".

Gavin A. Schmidt, Drew T. Shindell & Kostas Tsigaridis, Reconciling warming trends, Nature Geoscience 7, 158–160 (2014) doi:10.1038/ngeo2105 Published online 27 February 2014