Showing posts with label ozone hole. Show all posts
Showing posts with label ozone hole. Show all posts

Friday, December 4, 2009

The ozone hole isn't old news

Sigh. I thought the Antarctic 'ozone hole' was history, and I really wanted to leave global warming alone for awhile.

I'm warm and fuzzy about the subject, it's a ray of hope in our struggle to understand the planet and to survive on it. Back in the eighties, after about 10 years of studies and dithering, we all got together to come up with the Vienna Convention and the Montreal Protocol to phase out ozone-depleting chemicals because they were threatening us with too much exposure to ultraviolet light.

They agreements have been wildly successful, so much so that I was only mildly interested when NASA's Earth Observatory sent me yet another story back in September. (I'm hopelessly addicted to maps, so I got stuck looking at its fluctuations over 30 years-- the illustration here is from 2009). There were no great surprises: the decline in ozone appears to have stopped, and experts expect full recovery around 2050. The chemicals all have different 'lives' in the atmosphere, but the biggest villains last about 40-50 years.

Then, yesterday, I read that Seas could rise 1.4m, warns Antarctic climate review. Again, I was interested-- not wildly, but mildly. I seem to run across new temperature or sea level predictions every week or so. "Throw it into the hopper," say I, "let the scientists argue it out. They can try to convince me when they've reached a consensus."

That was before this simple statement rattled my cage:
For the past 30 years, the hole in the atmosphere's ozone layer above Antarctica has protected the bulk of the continent from the effects of climate change by generating fierce winds. In that time, sea ice around the continent has increased by 10 per cent.
We can't just quip 'be careful what you ask for' and start destroying ozone again; there was a reason for banning those chemicals. The UV levels would have fried our skin, our brains and toasted our DNA.

It sure wiped the smile off of my face.