CFCs are coming back to wreck the Earth’s ozone layer, and no one knows exactly where they’re coming from.
It’s been 31 years since the Montreal Protocol was signed banning the use of what was then considered one of the most useful chemicals we’d ever invented.
CFCs – chlorofluorcarbons – once powered everything from our fridges to our deodorant cans. They were widely used because they were easily controlled, were great for fighting fires and – so we thought – not particularly toxic.
Until scientists discovered CFCs were eating a hole in Earth’s ozone layer, particularly over Antarctica. So on March 2, 1989, 12 Eurpoean countries pledged to ban all production of CFCs by the year 2000.
The Montreal Protocol caught on, and by 2010, CFC production was supposed to be out of production worldwide by 2010. Of course, that boosted the price of black market CFCs, so it’s never been 100% effective.
But the rate of CFC emissions still dropped significantly, and consistently, right up to 2012, when its decline suddenly slowed by around 50%.
A study published in Nature this week found that emissions of one particular type, CFC-11, then started to rise. Between 2014 and 2016, it rose by as much as 25% on the average levels in the atmosphere from between 2002 and 2012.
Here’s the chart:
As a comparison, here are the rates of the other two damaging CFCs:
“We’re raising a flag to the global community to say, ‘This is what’s going on, and it is taking us away from timely recovery of the ozone layer’,” the study’s lead author, US National Oceanic and Atmospheric Administration scientist Stephen Montzka said.
It’s the first time that emissions of one of the three long-lived forms of CFC has increased for a sustained period since the late 80s.
CFC-11 is the version that was most widely used in fridges, freezers and foam building insulation back in the bad old days.
Why it’s building up again in the Earth’s atmosphere is obvious – someone is producing it again, and Montzka says no one knows whether “it is being made for some specific purpose, or inadvertently as a side product of some other chemical process”.
Where it is coming from is the other big question. NOAA doesn’t want to point fingers, but how about “East Asia” for starters?
Its research team ruled out CFC-11 being released from destruction of old buildings with the old style insultaion because the data didn’t fit. And any changes in wind patterns and atmospheric conditions over time don’t add up either, because other gas emissions haven’t increased.
The only answer is simply an increase in use, and because CFC concentrations have increased in the Southern Hemisphere more than the Northern Hemisphere, “somewhere in East Asia” is the most likely culprit.
“The increase in emission of CFC-11 appears unrelated to past production; this suggests unreported new production,” the study notes.
All Montzka would say about that is “further work is needed to figure out exactly why emissions of CFC-11 are increasing, and if something can be done about it soon.”
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