Assuming the global monitoring can track the source (if it was intentional or not), is not based on information from the article. > This is what happened a few

Assuming the global monitoring can track the source (if it was intentional or not), is not based on information from the article. > This is what happened a few years ago, when researchers detected high levels of CFC-11 in the atmosphere2, and traced them to eastern China3. They deduced the source on the basis of readings from monitoring stations in South Korea and Japan, reporting it in May 2019, and afterwards, levels began to fall. Scientists got somewhat lucky with CFC-11: monitoring stations equipped to detect that particular chemical happened to be located relatively close to the source. Maybe we just need to be lucky again?