An ozone hole opened up this past spring over the Arctic. Not good. While we have had thinning before, this is new. This isn't breaking news - it was in April - but an international team of scientists just had their study published in the journal Nature yesterday. I was on Al Jazeera English news last night trying to explain it.
That's a complicated task; aside from the fact that some people are confused that the ozone hole is what lets in all that global warming, and that the ongoing melt down of the Arctic sea ice gets a lot of attention, this discovery of an ozone hole at the north pole is disturbing and the science is complex.
We all remember the ozone hole in Antarctica, (which by the way still exists and is having a really bad year in 2011) linked to the emissions of chlorine in CFCs by research from Rowland and Molina, who won the Nobel Prize for their work in the 1970s revealing this threat. That's almost 40 years ago and it will take another 40 years to heal the ozone layer if all goes well... 80 years.
Bottom line is about six companies, including Dupont, Honeywell, Arkema and Solvay are responsible for manufacturing the majority of the chlorine-contaning CFCs (FREON was the most common brand name) that have loaded the stratosphere with chlorine, continuing to erode the ozone layer today and for decades to come.
In fact, ozone depleting chemicals are still being emitted in spite of the success of the Montreal Protocol and the whole mess of F-gases the CFCs and the HFCs and HCFCs that replaced them are now causing a large slice of the global warming we are feeling. Methyl bromide, an ozone depleting pesticide is used under a 'critical use exemption' filed annually by the US Government for tomatoes and strawberries... critical to certain farmers wallets.
CFCs were used in everything from hair spray to foam to refrigerators and air conditioners. These chemicals were built to be tough and when they leaked or were sprayed into the atmosphere they last a long time... so long that they are able to drift 15 miles (25 km) up in the sky to the thick of the ozone layer. That layer has the same effect as wearing 70 SPF sun block - when its not there, we burn badly.
Think about that for a minute... that thin delicate atmosphere that keeps us warm from the cold of space and the ozone layer protects us from the suns radiation, the crucial part is only 15 miles up...from you to the next town, straight up, thin as the skin on an apple.
What happened this spring in the Arctic is an unprecedented cold spot caused by a vortex over the north pole. When it's really cold, like minus 70C, ice crystals and particles provide the surface for the ozone destroying chlorine to do its nasty work on the O3 Ozone and break it apart.
Scientists are wondering if this Arctic ozone hole will become more common. They are worried that the ozone hole travelled over inhabited regions by late March - Scandanavia, northern Europe was receiving big doses of UV rays at that time. There have been papers in the past about the warming of the lower atmosphere trapping heat that should get back to the stratosphere and keep it too warm for ozone destruction to happen.
The health impacts of such events are not known, but exposure can cause skin cancer and cataracts.
The dangerous experiments with our atmosphere and the polar ecosystems continue.
Thanks for nothing Dupont.