Copyright is the wrong hammer -
firstly it will run out eventually.
Secondly, copyright holder can die, coupyright could be sold, and new owner could be irresponsible, litigious, and repurpose the symbol for a brand of coffee.
Then what, should all labs and scientists in the world find a new symbol?
The only solution is to treat misuse of the symbol same way we treat misusing emergency services.
I was first thinking of laws, but they are slow & contentious to pass (esp with one party consistently acting in bad faith), so I quickly landed on copyright, which of course has all the problems you cite and more.
Maybe start with (C), and pass laws to implement your solution? Or, maybe there's a way prosecutors can leverage existing laws.
IANAL, but I believe trademark protection is more applicable here. Firstly, it is more applicable to an identifying mark, symbol or logo. And it can be renewed indefinitely.
Secondly, copyright holder can die, coupyright could be sold, and new owner could be irresponsible, litigious, and repurpose the symbol for a brand of coffee.
Then what, should all labs and scientists in the world find a new symbol?
The only solution is to treat misuse of the symbol same way we treat misusing emergency services.