Tuesday, April 07, 2020

Arctic ozone holes? What new hell is this?

If you thought that ozone holes were a thing of the past, then you're not keeping up with the science.
Didn't the Antarctic ozone hole get fixed by the 1987 Montreal Protocol and regulation of chlorofluorocarbons (CFC) in refrigerators? Isn't that touted as one of the few major victories for the environmental movement?
Well, yes, but ozone holes are still around.
It turns out that both the Antarctic and Arctic poles lose ozone every year, as low temperatures and polar vortices cause cloud cover to clump together, which allows chlorines and bromines from human industrial processes to penetrate the atmosphere and eat away at the protective ozone layer. Holes as large as 20 to 25 million square kilometers still regularly appear over Antarctica, and may last for 3 to 4 months during the Antarctic winter, but they do close up again as the weather warms.
Ozone holes over the Arctic can also appear but, because temperatures tend not to dip so low, they tend to be much smaller. What's brought them into the news now is that, due extreme weather, the 2020 Arctic ozone hole was the largest ever recorded at about 1 million square kilometers. Tiny, compared to Antarctica, but there are much larger human, animal and plant populations near the Arctic pole compared to the Antarctic.
Is this a problem? Is it a growing trend? With typical scientific reticence, climatographers are saying that only time will tell.

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