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My understanding is that the first time anyone actually measured the ozone concentration in the Antarctic atmosphere during winter was the early 1980's. My guess is the ozone hole has been around for a lot longer than the 1980's.

The ozone hole was first discovered due to ground-based measurements made by the British Antarctic Survey at Halley Bay, Antarctica; the measurements commenced in the 1950s. The decline in ozone was noted first here; instrumental observations from satellites had been corrected because the occurrence of the hole was first thought to be an instrumental anomaly.

The figure below shows the record of ozone measurements in October at Halley Bay.

I should read all the posts before asking a question.

Your plot is interesting and sure suggests that the ozone concentration has been reduced. But I worry about the distortion of plotting averages. I would be interested to see how the results look if they were plotted monthly.

What in the world in the data shows that this is not a natural variation? Yes, there is a correlation to CFC use and the recorded reduction of ozone levels, but I think you would also find a similar correlation with federal spending, breast cancer, or the number of scientists stationed in antartica.

Correlation dose not show cause and effect – and this is not anything like a cyclic correlation – it is just a trend – and a simple trend has a 50% chance of being in the right direction to support a theory linking it to a second trend.

Now if the ozone begins to go back up as measured CFC levels drop you have a one time signal – still not exactly science yet.

Several other possibilities exist that could just as easily explain such trends – such as lower stratospheric temperatures.

Of course that leaves out any connection with a danger of UV radiation at ground level – if the ozone is depleted in the stratosphere, UV light would tend to create ozone at lower elevations (and warmer air).

Then you have to deal with the problem that there never was any measured increase in UV radiation other than at the poles where people don't live.

Now just so no one gets the wrong idea – I have not disproved anything. CFC could be causing this ozone phenomena – I'm only showing that we don't really know. Getting federal grants and working at university does not mean there is real science going on, but there does seem to be a lot of real politics going on.