Ah the ozone hole. I remember years ago when, going door to door for Greenpeace USA, I could barely find anyone except NASA scientists who even believed the thing existed.
Yet, just last Wednesday, the Antarctic ozone hole reached an all time big. But not to worry say scientists. This year's unusually large hole was due mostly to an extended South Pole cold spell. As the San Francisco Gate reports, the overall situation is looking good:
In fact, separate measurements show the amount of ozone-depleting bromine and chlorine gases at the surface peaked around 1995, and has been declining since then, mainly because of international restrictions adopted under the 1987 Montreal Protocol.
The dangerous gases can persist for two human generations, however, and it takes a long time for surface trends to make a measurable difference high up. At the level of the stratosphere, which starts about 9 miles above the surface, chlorine gas measurements peaked about 2001.
Scientists said they expect the ozone layer will have fully recovered sometime around 2065-2075 -- just in time for global warming to have a shot at destroying all life on Earth.
Ooop! Well, maybe not ALL good. But glad to here we've got that ozone thing covered at least. Now just to sort that small problem of climate change!