I have been hearing mummers that the theory we humans were responsible for ozone hole was about to challenged. Here is an explanation from the Reference Frame. Read the whole article here, it is rather complex. But this is the bottom line.
Even though this should have been a good enough reason to make lab experiments with all these compounds, NASA's Jet Propulsion Laboratory apparently did these experiments only recently. Their experiments were probably not trivial and required some low-temperature engineering. What is their result for the rate of photolysis of Cl₂O₂?
• It is almost ten times smaller than needed for the existing ozone hole theories.
That's a huge problem. But only Markus Rex of Potsdam was brave enough to look at the ozone depletion theory with these new data. A lot of things have obviously changed. A dramatic conclusion is that
• At least 60% of observed ozone depletion is due to an unknown mechanism.
At least all quantitative features of the models - that have been considered a part of the "scientific consensus" - suddenly become uncertain again. One modest implication is that we certainly no longer know which molecules are actually important for ozone depletion and whether most of this process is due to completely different reasons, perhaps unrelated to chlorine and bromine.
So, how did we arrive at the first consensus. Curve fitting the out put from computer models, just like we are doing for global warming today. From the Reference Frame:
Well, this is curve-fitting and such estimates may often be wrong. As we have repeatedly emphasized, you shouldn't be fitting a few quantities to get a simple description of a complicated system.
And, this exactly what the climate change modelers are doing. If it did not work for ozone depletion, why should it work for global warming climate models? Maybe we can get an answer in the comments.