> Apparently they don't just completely vaporize, but instead leave behind micro particles that float around for a long time.
That's not clear. There's no empirical evidence of it, and the computer models we have don't have definitive results.
Those alarms are not really proper.
Ignoring problems until they become too big to pooh-pooh away is how we got into the climate crisis. And some countries are still pooh-poohing it away.