Loss of habitat for human animals could result from at least six different factors rooted in civilization. Some are nearer than others. Half fall under the broad category of abrupt climate change. Two of the remaining three fall under the heading of ionizing radiation, hence lethal mutations.

I’m doubtless missing a few factors. In addition, I’m not mentioning the interactions between them, which surely will accelerate the process by which humans exit the planetary stage. But, as always, any number can play.

The usual initial response to the notion that Homo sapiens will become extinct is swift denial. As with every other species on the planet, lack of habitat will doom us, too. I welcome rational evidence to the contrary. In contrast, I expect irrational commentary free from the shackles of evidence (if not in this space, then certainly elsewhere). In general, denial-based commentary will exhibit…