30 October 2015: added link to paper (see at the end)
I just read a short article by Steve Goreham titled “Did we really save the ozone layer?” (link).
After the Montreal Protocol most nations were phasing out their use of ozone depleting substances (ODS, like freon), and since about 20 years there are practically no much human emissions left. Remember that these evil fluor-carbon molecules are seen as the culprits causing the yearly thinning of the ozone layer above Antarctica (the Ozone Hole). During October and November total zone column may plunge to 100 DU in that hole.
Has this phasing out of ODS fostered a closing of the zone hole? Really not, as shown by this graph:
Since 1996, the area of the ozone hole remains more or less at 20 to 25 millions km2, while the ODS consumption and emission (red curve) fall to zero. Could it be that the whole theory (which gave Molina and Roland their 1995 Nobel price) is either bogus or at least incomplete? The ozone destroying chemical reactions found by the 2 Nobelist certainly exist; there remains the nagging suspicion that other, possibly more important ozone munching phenomena as the human ODS emissions might be at work.
How inconvenient that Nature so often refuses to obey our glorious models and the political decisions based on them!
30 October 2015:
See this paper by Gribble: (paywalled):
The diversity of naturally produced organohalogens.
“More than 3800 organohalogen compounds, mainly containing chlorine or bromine but a few with iodine and fluorine, are produced by living organisms or are formed during natural abiogenic processes, such as volcanoes, forest fires, and other geothermal processes. The oceans are the single largest source of biogenic organohalogens, which are biosynthesized by myriad seaweeds, sponges, corals, tunicates, bacteria, and other marine life. Terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and even humans also account for a diverse collection of organohalogens.”