This is the best tl;dr I could make, original reduced by 84%. (I’m a bot)
A sharp and mysterious rise in emissions of a key ozone-destroying chemical has been detected by scientists, despite its production being banned around the world.
Since 2007, there has been essentially zero reported production of CFC-11, the second most damaging of all CFCs. The rise in CFC-11 was revealed by Stephen Montzka, at the US National Oceanic and Atmospheric Administration in Colorado, and colleagues who monitor chemicals in the atmosphere.
Michaela Hegglin, at the University of Reading, UK, and not part of the research team said researchers had taken rigorous steps to rule out alternative explanations for the rise in CFC-11 when reaching their conclusion that new production must be occurring.