Dear Colleagues: Yesterday, a student in one of my courses asked me about the role, if any, methane gas in the destruction of the ozone layer. I gave the CFCs explanation and promised to look for additional information on methane. This site,
http://www.theozonehole.com/ozonedestruction.htm (cced) seems to suggest that radicals from methane form in the stratosphere have a role, "Methane (CH4), chlorofluorocarbons (CFCs), nitrous oxide (N2O) and water are injected into the stratosphere through towering tropical cumulus clouds. These compounds are broken down by the ultraviolet radiation in the stratosphere. Byproducts of the breakdown of these chemicals form “radicals”—such as nitrogen dioxide (NO2) and chlorine monoxide (ClO)—that play an active role in ozone destruction. " Later on, the same site seems to attribute another role for methane: "Due to this catalytic cycle, one atom of Cl can destroy thousands of ozone molecules before it is passivated through reaction with NO2, methane or other substances." Could anyone provide illumination (e.g. are the statements about methane supported scientifically? If "yes", what is its relative contibution of methane compared to CFCs) or some constructive feedback directly to me? blayjo...@gmail.com Gratefully, Jorge Jorge A. Santiago-Blay, PhD blaypublishers.com 1. Positive experiences for authors of papers published in *LEB* http://blaypublishers.com/testimonials/ 2. Free examples of papers published in *LEB*: http://blaypublishers.com/category/previous-issues/. 3. *Guidelines for Authors* and page charges of *LEB*: http://blaypublishers.com/archives/ *.* 4. Want to subscribe to *LEB*? http://blaypublishers.com/subscriptions/ http://blayjorge.wordpress.com/ http://paleobiology.si.edu/staff/individuals/santiagoblay.cfm
