I've gone to jail to make nuclear weapons illegal but it's climate change that makes me believe homo sapiens time is up.

I don't think most people realize the threat, having lived under it for 75 years.
It is interesting to note that during the Cuban Missile Crisis of 1962, 40 million Americans took it seriously enough to leave their homes, and head for rural areas. That would be equivalent to 80 million doing that today.
You are not being paranoid. The threat is real .
Give Humans the ability to cast artificial Sun Bombs at their enemies, and they will!

Start playing poker, Kathleen, and learn how to bluff.

Fourteen-year-olds ought to know, so start with your youngster. Limit bets to “Who does the laundry this week?” et cetera.

I am not fond of the idea of dying, much less being flash roasted. But, we all die and have no power to stop it. I had a period of severe paranoia about it when Reagan put Pershing missiles in Europe.

The main thing is that there isn't much to destroy in Ukraine. Right now, the only target of value is Kiev, and if it were destroyed, it would be seen as a act of petulant revenge rather than military strategy. The Russians don't really have much they can do that isn't a war crime or crime against humanity.

They've expended significant effort to pretend they weren't responsible for the use of gas in Syria. There'd be no covering this up and no drowning demands for regime change (no end to sanctions).

I don't think they will blow up the world but I fear that someone will detonate a device. It hasn't happened since 1945 but once some country breaks the ice, there's no going back.

Nuke! No Way, Don't worry at all. NATO is ready!
oh, against Nuke danger there isn't anything to do as a citizen, governments are sober enough.