And on top of that, inter-government cooperation to tackle a global problem. Like we had to address CFCs pollution. With the political will to sanction countries that deny the evidence and won't play ball.
It's still being solved, in the sense that CFCs in the atmosphere aren't zero but they are decreasing. The new emissions were only a minor setback. From the article you linked:
> Atmospheric chlorine levels are still decreasing but more slowly than expected
https://www.cnn.com/2019/05/22/health/china-cfc-pollution-en...