Thursday, November 11, 2010

Self-Rejuvenating Ozone layer?

Ozone depletion is the cumulated decrease of ozone over the last few decades in the Earths Stratosphere. It was first observed in the late 1970’s and found to be caused primarily by halogen atoms chlorine and bromine which are found in chlorofluorocarbon compounds (CFC)(Glenn 1998). These substances are mostly found in refrigerators and aerosols. In order to prevent irreversible damage to the stratosphere, an international treaty was created September 16, 1987, to protect the depletion of ozone levels (Glenn 1998). This treaty is famously recognized as the Montreal Protocol, the treaty outlined the ban of chemical substances commonly used that are believed to cause the destruction of ozone (CFC’s).

In the Australian Geographic journal article, “Ozone layer on the mend, says report” (September 17, 2010), the author makes numerous pretentious claims, without proper supporting evidence. Primarily he claims that ozone depletion in our stratosphere has stopped completely, solely due to the ban of harmful CFC compounds (AAP 2010). Also he gives the assumption that only CFC’s compounds cause ozone depletion by claiming that the Montreal Protocol (1987) has sheltered us from the furthering of ozone decay. Additionally the author argues that the level of ozone in our atmosphere will be reestablished fully to levels around the 1980’s by 2045( AAP 2010). In every statement proposed, the author provides no evidence or data whatsoever to support and strengthen the claims made. Nor does the author anticipate the criticism to the claims and provide a rebuttal to disprove opposition. Due to the extreme lack of evidence to build its case the article provides a very weak argument.

Fig 1. Gas trends in ozone decay between 1992 to 2008.

The claim that the Earth’s ozone layer has stopped depleting completely, although it contains a fragment of truth, it is very drastic. There is data available that supports the claim that the rate of ozone depletion due to CFC specifically has decreased (Figure 1), however the generalization that it has stopped thinning completely is not evidently supported. The article also gives the reader the impression that only CFC compounds contribute to the decay of the stratosphere. This is not the case, CFC compounds make up only 80% of the harmful free radicals that are degrading the ozone layer (Bora 2009). Greenhouses gases are also important contributors to global warming and ozone depletion, however the article does not mention these factors.The article also gives the reader the impression that all harmful chlorine compounds that negatively impact the levels of ozone come from man made products such as refrigerators. Contrary to the impression given, not all of these chlorine based compounds are man made, 18% of the ozone depleting compounds are naturally produced in our environment , as seen in figure 2 (Glenn 1998).The journal article claims that the ozone hole in the stratosphere will not only be reduced to its original state in the 80’s by 2045, but it declares that the ozone hole may actually disappear in the future (AAP 2010). There is no actual evidence provided to support such an allegation in the article, thus making the claim arbitrary. Not only does the author provide inadequate evidence, but he also fails to provide any details about the method of how such claims were formed. The article does not supply the reader with any information in regards to how the researchers came up with their conclusions. Therefore this journal article fails as an informative piece of literature as it does not accomplish its objective, which should be to inform the public on a specific issue. It does provide enough supporting information in order for the reader to make an informed decision on the topic. Due to the fact that the author does not provide information on how the conclusions were reached, the reader does not know if the claim is reliable because there is uncertainty on the amount of experimental data collected.

Fig 2- The origin of harmful chlorine compounds in atmosphere.

Another flaw in the journals argument is the fact that the author contradicts himself quite often near the end of the article. The majority of the article consists of many allegations stating that the diminishing of the ozone layer has permanently stopped thanks to the ban of harmful chemicals, and that scientists have proclaimed that by 2045 to 2060 by the latest, the amount of ozone in the stratosphere will be identical to conditions in the 1980’s( AAP 2010). However the article also states that scientists are still in the midst of learning and understanding completely the implications and effects of ozone decay and global warming. How can the author confidently claim that the scientists “findings” that our stratosphere will be much healthier in 35 years is true if he also states that the scientific community has much to learn about ozone depletion interactions? By contradicting himself, the author decreases the value of the information in the article, therefore weakening his arguments and claims.

In conclusion the author of the journal article presents an extremely weak argument. Not only is there no information provided to support each claim presented, but the author leaves out many crucial details needed for the reader to fully understand how such conclusions were drawn. He neglects many other contributing factors to ozone depletion, thereby further restricting the information available to the public. The authors position is not solidified due to the lack of information in the journal. Additionally because not enough information is provided to inform the public, the author fails to anticipate opposition or criticism which reduces the strength of the claims. In order to be considered a more reliable source, I believe that a greater depth of research is needed on the topic, in order to provide more evidential data.


P, A. A. "Ozone Layer on the Mend, Says Report." Australian Geographic. 17 Sept. 2010. Web. 09 Nov. 2010. report.htm>.

Bora, By Chandramita. "Ozone Layer Depletion: Effects and Causes of Ozone Depletion." Buzzle Web Portal: Intelligent Life on the Web. 2009. Web. 11 Nov. 2010. .

Carver, Glenn. "The Ozone Hole Tour : Part III. The Science of the Ozone Hole." Centre for Atmospheric Science. University of Cambridge, 1998. Web. 11 Nov. 2010.

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