20 years ago, even 15, there were still plausible solution sets that didn't require half the human race to die.
I do not believe there are, any longer.
Conversation
I thought about contingencies, but for now I've just settled on diversifying my finances slowly while I plod on through life.
If the people I care about are probably not going to live to old age, it seems wasteful to spend youth fretting over it.