I didn't discover that lemmy.world has a Scunthorpe Problem auto-censor editing your comments for you (and mine, but only if you're reading them on lemmy.world) so I'm actually not sure if you're making a joke or are unaware of what's happening!
As a result of the scientific findings and the possible severe impacts of ozone depletion, governments around the world began passing laws reducing or banning the production of CFCs and other ODSs. This culminated in the Montreal Protocol, agreed in 1987, which has now been signed by every member state of the United Nations. Signatories to the Montreal Protocol have agreed to phase out ODSs and replace them with less-damaging substances.
Since the passing of the Montreal Protocol, the emissions of ODSs have fallen to a fraction of their levels in the early 1980s and the ozone layer has begun to recover. The hole in the ozone layer over Antarctica still exists, but it has been slowly shrinking over the past two decades thanks to concerted international action.
"Snickering", as far as I can tell is just the American version of "sniggering". I can't track down the etymology of the split and so I can't see any huge mentions of "it sounded a bit racist so we changed it" but I guess it seems plausible given things like "titbit" being changed to "tidbit".
While someone saying "niggardly" is a bit suspicious given that it's a pretty archaic word that most people haven't even heard of, "sniggering" is a pretty normal word to use in Britain. I imagine if some racist wants to start using it as a bit of coded bigotry they could, American-branded homophobia has already ruined the word "fags" to describe your cigs!
I did a quick search after the other replies came in, scientific consensus seems to be "more research required to be scientific about it, but looks like there are way less bugs about'
Probably a lot safer to just not give a gun to a child