Global ozone layer depletion leveling off – rising slightly

Common myths about ozone depletion:
Myth: CFCs cannot reach the stratosphere because they are heavier than air.
Fact: Air in the lower atmosphere (which extends far above the stratosphere) moves in masses, not as individual molecules. A number of studies have found CFCs and the products of their breakdown in the stratosphere (Rowland, EPA).
Myth: Volcanoes and other natural sources contribute much more chlorine than CFCs to the ozone layer.
Fact: Chlorine compounds from natural sources are soluble, and so are washed out of the atmosphere. CFCs, by contrast, are not soluble and so are able to reach the stratosphere. A number of studies have shown that the majority of chlorine in the stratosphere comes from man-made chemicals (Rowland, Taubes, Russell et al, EPA).
Myth: The Antarctic ozone “hole” was there all along, it was discovered in the 1970’s because that’s when satellite measurements started.
Fact: The hole was discovered using a ground based instrument that had been in use since 1956. There was no hole until about 1976. That means about 20 years with no hole. Since the 70s the hole has continued to increase in size and intensity (Farman, et al, Jones & Shanklin).
Myth: The “hole” was present when the first measurements were made in 1956.
Fact: The first ozone measurements made in the Antarctic were lower than similar measurements made in the Arctic. However, this is the natural condition, not the decrease that is referred to as the ozone “hole”. As noted above, there was no “hole” during the first 20 or so years of measurement. (Parson, Christie).
Myth: Some French researchers found an ozone hole in 1958.
Fact: Paul A. Newman (Newman) looked at all the facts and found that “There is no credible evidence for an ozone hole in 1958.”
Myth: Spray cans deplete the ozone layer.
Fact: Spray cans (in the United States) have not used CFCs as propellants for about 20 years.
Myth: Of course there is an ozone hole in the winter, there is no sunlight to make new ozone.
Fact: The ozone hole occurs in the spring, after the sunlight returns. There is little destruction or creation of ozone during the winter (Parson)
Myth: DuPont supported the ban on freon because the patent was about to run out.
Fact: The patent for making freon was issued in 1928, it ran out in the 1940s, long before any concern about ozone depletion. (The History of Freon)
Jim Norton- http://info-pollution.com/common.htm

Greendoubts (09:32:15)
You are of course correct Bill is not my name.
My real name would probably mean nothing or everything to you. Posting anonimously means What I Post stand or falls on its veracity and content not on my status in the scientific community.
I stand by all I post and often will post AGW and non-AGW information (e.g. bill (08:58:04) : I could easily have missed out the final paragraph. But despite being a greenie, a probable warmist, a believer in “windmills” I really only want the truth.!!!!
Seing others post unsubstantiated “truths” makes me mad!

Bill said
“Fact: The hole was discovered using a ground based instrument that had been in use since 1956. There was no hole until about 1976. That means about 20 years with no hole. Since the 70s the hole has continued to increase in size and intensity (Farman, et al, Jones & Shanklin).”
Bill you are making an assumption .In my earlier post I said:
“TonyB (01:05:36) :
The most famous example of previous ozone depletion is the ‘hole’ over the antarctic. I once posed this question to the Max Planck Institute and Cambridge University
“How do we know that there hasn’t ALWAYS been an ‘ozone hole’ over the Antarctic-and that it varies in size?”
This was in the same sort of vein of investigation that I queried (with very good cause) the assumption that arctice ice is at an unprecented low level because we only record since 1979 and don’t consider longer cycles.
This is a reply to my email-the preliminaries confirmed the assumption I made that we don’t know for certain, and then went on: (there then folows other informationI colected together at the time).
***
“Thank you for your email. Here are some replies to the points you raise.
1 Measurements of ozone over Antarctica started in 1956 from ground stations and show that levels were roughly constant until around 1980. The satellite record started in 1970 and has been continuous since 1979. The two records are entirely consistent with each other and with other measurements such as the vertical distribution of ozone measured by ozonesondes and upper air temperature and wind measurements. The length of geophysical records is an important consideration in their interpretation, and it is always important to see how consistent our understanding (theoretical and related measurements) of the current situation is with the long-term behaviour. In the case of the Antarctic ozone hole, there is additional overwhelming evidence that the combination of atmospheric dynamics and the atmospheric chemistry related to CFCs causes the annual decline in ozone each year. Basically we can see that the annual decline is cause by chlorine chemistry and we know that stratospheric chlorine comes principally from CFC which were not present, say, a hundred years ago. The evidence is very well documented in a number of places and I will not repeat it here. The question as to whether conditions in the past could have led to an ozone hole by a completely different mechanism is an interesting one, but it does not affect our confidence in the fact that CFCs are responsible for the current ozone hole.
2. The new laboratory measurement of Cl2O2 by Pope et al has received a great deal of scientific attention internationally over the last year. As discussed by Pope et al., the analysis of the raw laboratory measurements is tricky and has uncertainties associated with it. Four independent laboratory groups are making new measurements of the process with different techniques and I anticipate that the results will be known in the next few months. In the meantime, careful analysis of existing laboratory and field measurements shows that either we are missing an important constituent which behaves like Cl2O2 or the new measurement is in error. Only time will tell which is right.
3. To the best of my knowledge, Qing-Bin Lu was not involved in any way in the Pope et al. study. He/she was certainly not involved as an author and is not mentioned in the acknowledgements. My views on the atmospheric relevance of Qing-Bin Lu’s work (completely different to the Pope et al work) are best described in my comment on his/her Phys Rev Lett paper in 2001 published subsequently in that journal. I have seen nothing in subsequent publications by Dr Lu to change my view that the atmospheric significance of the processes under consideration is small at most. I agree fully with R. Muller’s comment on Dr Lu’s most recent paper.
I hope these answers suffice.
Yours
(name deleted as it was a private email)
Item 3) The following posts came from Watts up and I have collected them together as they are obviously relevant;
Dr. Linwood Callis of NASA led an agency investigation of the causes of ozone fluctuations during the 1980s. As he told me: “The overwhelming portion of the ozone depletion in the 1980s was due to natural causes,” and the effect of CFCs “was really quite small — less than one-half of one percent.” (His paper “Ozone Depletion in the High Latitude Lower Stratosphere: 1979-1990″ appeared in the Journal of Geophysical Research, Vol. 96, No. D2, Feb. 20, 1991, pp. 2921-2937.) Callis went on to say that he thought that scientists blaming CFCs for ozone depletion were being “less than honest.”
Another one bites the dust.
http://ftp.vix.com/objectivism/Writing/RobertBidinotto/OzoneDepletion.html
Item 4 Leif Svalgaard (13:18:35) :
Ferdinand Engelbeen (11:24:06) :
Is this not more a question of a less active sun in general, where the cosmic rays are inversely coupled to?
Seems likely to me, but I need to see the original article. I have great ‘admiration’ for NASA’s ability to blow something out of proportion and label it as “New”, “breakthrough”, “important”, etc.
dmdoug (11:37:22) :
Is this caused by the shrinking heliosphere?
No, the cosmic ray intensity now is not any larger than it usually is a every solar minimum. On http://www.swpc.noaa.gov/alerts/solar_indices.html look for Neutron Monitor % of background, Oct 24 100.0 %
The ‘background’ is the normal long-term intensity when there is no solar modulation.
Cosmic rays have always been around. So the ozone hole during the Maunder and Dalton minima [where many people (including the Heartland Institute representatives) claim less solar activity -> more cosmic rays -> LIA] should have been larger than now if the primary driver of Ozone hole size was cosmic rays. So, next month’s hole would not be the largest, unless, of course, helped along by CFCs.
Item 5
My daughter-in-law [Signe] had a review article in Nature a couple years back. They concluded:
“Nature 441, 39-45 (4 May 2006) | doi:10.1038/nature04746
The search for signs of recovery of the ozone layer
Elizabeth C. Weatherhead & Signe Bech Andersen
Abstract
Evidence of mid-latitude ozone depletion and proof that the Antarctic ozone hole was caused by humans spurred policy makers from the late 1980s onwards to ratify the Montreal Protocol and subsequent treaties, legislating for reduced production of ozone-depleting substances. The case of anthropogenic ozone loss has often been cited since as a success story of international agreements in the regulation of environmental pollution. Although recent data suggest that total column ozone abundances have at least not decreased over the past eight years for most of the world, it is still uncertain whether this improvement is actually attributable to the observed decline in the amount of ozone-depleting substances in the Earth’s atmosphere. The high natural variability in ozone abundances, due in part to the solar cycle as well as changes in transport and temperature, could override the relatively small changes expected from the recent decrease in ozone-depleting substances. Whatever the benefits of the Montreal agreement, recovery of ozone is likely to occur in a different atmospheric environment, with changes expected in atmospheric transport, temperature and important trace gases. It is therefore unlikely that ozone will stabilize at levels observed before 1980, when a decline in ozone concentrations was first observed.
Item 6
(Some of this contains material that repeats the news source I quoted in Item 1)
There are some big problems with the CFC-ozone causal link claimed by promoters of the Montreal protocol. There was a paper in Nature last year from NASA JPL that reported measured reaction rates for one particular chemical pathway to be much too slow compared with the assumed reaction rate that led to the predictions of ozone destruction rates from A-CFC’s.
http://www.junkscience.com/sep07/Chemists_poke_holes_in_ozone_theory.htm
Some of the quotes from the authors and other atmospheric chemistry/ozone experts are very enlightening. For example,
“This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” What effect the results have on projections of the speed or extent of ozone depletion remains unclear.”
“The rapid photolysis of Cl2O2 is a key reaction in the chemical model of ozone destruction developed 20 years ago2 (see graphic). If the rate is substantially lower than previously thought, then it would not be possible to create enough aggressive chlorine radicals to explain the observed ozone losses at high latitudes, says Rex. The extent of the discrepancy became apparent only when he incorporated the new photolysis rate into a chemical model of ozone depletion. The result was a shock: at least 60% of ozone destruction at the poles seems to be due to an unknown mechanism, Rex told a meeting of stratosphere researchers in Bremen, Germany, last week.”
“Other groups have yet to confirm the new photolysis rate, but the conundrum is already causing much debate and uncertainty in the ozone research community. “Our understanding of chloride chemistry has really been blown apart,” says John Crowley, an ozone researcher at the Max Planck Institute of Chemistry in Mainz, Germany.”
“Until recently everything looked like it fitted nicely,” agrees Neil Harris, an atmosphere scientist who heads the European Ozone Research Coordinating Unit at the University of Cambridge, UK. “Now suddenly it’s like a plank has been pulled out of a bridge.”
But Montreal Protocolists continue to point to the ’success’ of the CFC-banning protocol as a blueprint for carbon dioxide controlling protocols. I guess it depends on your measure and definition of ’success’.
***
Bill, sorry for the length of this post but I hope you find it of relevance. Now I make no claims either way ( I leave that to Qing Bon Lu whose research I quoted). I find the subject of theoretical interest because it deals with an ‘assumption’ that ‘we’ caused the hole. I have no particlar viewpoint other than to say it is nowhere as clear cut as you state, and our historic knowledge of any hole-man made or otherwisde-relies on very recent historical measaurement. I am just being a sceptic 🙂
tonyb

solar effect on O3 – reduction should be global and largest reduction at equator where solar inpact stongest.
GCR – blatting the o3 bond. GCRs are modulated by 11 year solarcycle so ozone depletion should show this. Concentrated at poles by magnetic field??
Calis predicted in 1987 that the ozone depletion had peaked see this interesting piece:
http://www.ecosmagazine.com/?act=view_file&file_id=EC52p7.pdf
ps. link http://ftp.vix.com%2Fobjectivism%2FWriting%2FRobertBidinotto%2FOzoneDepletion.html does not connect!
Now of course shown not the case.
Other theories of the time in this article.
The hole appears at the time the stratospheric clouds appear @-80C. So it may have something to do with this. Dr. Plumb (in article) suggests a recent (i.e. recent to 1987) drop of 20C at 30km could be the cause.
Unfortunately AMSU only goes back to early 90’s and I plotted only 25km height but here is a temp plot:
http://img512.imageshack.us/img512/6769/amsua19982009.jpg
If 25km is equiv to 30km then 2000 should have been large hole 2002 small hole and largest should be 2008. No time to check, unfortunately. But it does not seem to agree with the plots above.

bill (06:09:22) — Thanks for your link to Ozone Depletion
by Robert J. Bidinotto. He shows a nice balance and I gained from the reading.