No, I am not going to get into ozone depletion theory. While the science of anthropogenic ozone depletion has some uncertainties, the costs of abatement are radically lower, by order of magnitude, than for CO2-caused warming. This changes the cost-benefit ration of action radically, resulting in it making more sense to take action on CFC’s "on the come" or "just in case" than is the case for CO2.
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….
Nothing currently suggests that the role of CFCs must be called into question, Rex stresses. "Overwhelming evidence still suggests that anthropogenic emissions of CFCs and halons are the reason for the ozone loss. But we would be on much firmer ground if we could write down the correct chemical reactions."