NOTE: It has been pointed out to me by an email from a regular WUWT reader that some people get a different conclusion from the headline other than what I was thinking of. So, for those who didn’t read the paper fully to the conclusion, I offer this clarification:
In the conclusions of the paper here (PDF) there is this:
Thus, the above facts (1)–(5) force one to conclude that the CR-driven electron-induced reaction is the dominant mechanism for causing the polar O3 hole.
(CR stands for Cosmic Rays) The above conclusion is what I based my title on. The titled also merited a “may be” caveat until replication of the work is done by another scientist. Anyone reaching a different conclusion, such as one of CFC’s not being involved, is erroneous. Cosmic Rays are drivers (or some may say a catalyst) of a complex reaction involving CFC’s, resulting in ozone ‘O3‘ depletion, and that is what is referred to in the conclusion.
While I had considered changing the headline to make it clearer for those who don’t read scientific papers completely, substituting the word “responsible” with “a Catalyst”, doing so would break web links already in place, and that would appear to some that the article had been removed, when that would not be the case.
Comments are normally closed automatically after 60 days, but I’m opening them up again for a short period since there has been a change to the article.
The Antarctic Ozone Hole is said to be caused only by Chlorofluorocarbons (CFC’s). According to this new study, perhaps not. (h/t to John F. Hultquist)
Here is a new paper of interest just published in Physical Review Letters.
Correlation between Cosmic Rays and Ozone Depletion
Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
This Letter reports reliable satellite data in the period of 1980–2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008–2009 and probably another large hole around 2019–2020, according to the 11-yr CR cycle.
Excerpts from the paper:
There is interest in studying the effects of galactic cosmic rays (CRs) on Earth’s climate and environment, particularly on global cloud cover in low atmosphere (3 km) and ozone depletion in the stratosphere. The former has led to a different scenario for global warming, while the latter has provided an unrecognized mechanism for the formation of the O3 hole. The discovery of the CR-cloud correlation by Svensmark and Friis-Christensen has motivated the experiments to investigate the physical mechanism for the correlation. In contrast, the CR-driven electron reaction mechanism for O3 depletion was first unexpectedly revealed from laboratory measurements by Lu and Madey. Then the evidence of the correlation between CRs, chlorofluorocarbon (CFC) dissociation, and O3 loss was found from satellite data by Lu and Sanche: the O3 hole is exactly located in the polar stratosphere and at the altitude of 18 km where the CR ionization shows a maximum.
CRs are the only electron source in the stratosphere, while halogen(Cl, Br)-containing molecules are long known to have extremely large cross sections of dissociative attachments of low-energy electrons. The latter reaction will be greatly enhanced when halogenated molecules are adsorbed or buried at the surfaces of polar molecular ice, relevant to polar stratospheric cloud (PSC) ice in the winter polar stratosphere, as firstly discovered by Lu and Madey and subsequently confirmed by others in experiments and theoretical calculations.
Read the complete paper here (PDF)