https://phys.org/news/2018-07-ozone-hole-environmental-success-story.html

Then, a breakthrough. By running global climate models backwards, a team of scientists in Boulder, Colorado, trace the source of CFC-11 to East Asia. The trail is picked up by the Environmental Investigation Agency, a tiny activist organisation based above a coffee shop in Islington, London. EIA dispatches investigators to China and uncovers rampant illegal production of CFC-11 for insulation foam used in the Chinese construction industry. "This is an environmental crime on a massive scale," says Clare Perry, EIA's climate campaign leader.

Meanwhile, scientists and diplomats from around the world converge on Vienna for a meeting of the United Nations working group on the Montreal Protocol. EIA's blockbuster report is high on the agenda. But can the international community band together once more to protect the ozone layer and save "the world's most successful environmental treaty?"