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 ignorance of biology and ecology, despite the importance of these disciplines to understanding extinction.

If the following factors prove insufficient to convince you, I recommend visiting the nearest shopping mall. There, observe human behavior for an hour or two. If that’s not sufficiently convincing, you must have become part of the zombie hordes within industrial civilization. We have met the enemy, and … well, you know.

1. Abrupt climate change resulting from the loss of global dimming when civilization falls. I’ve spoken about this issue recently, and my presentations in the near future will continue to pound this drum.

2. Abrupt climate change resulting from firing the clathrate gun (item 1 on this list). I’ve written and spoken repeatedly about this topic.

3. Abrupt climate change resulting from moistening of the upper troposphere (item 39 on this list). As the planet warms, the most-abundant greenhouse gas becomes more abundant, thus further warming the planet.

4. Overt, rather than the ongoing covert version of World War leading to use of nuclear weapons. We can duck, but there’s no cover. So much for “duck and cover.”

5. Meltdown of the world’s nuclear power facilities. Fukushima was a harbinger. Many people, all of them more knowledgeable about the subject than me, believe Fukushima is an extinction-level event for our species.

6. Driving to extinction many other species. At some point, we become the species driven to extinction by industrial civilization. We will die without a living planet to sustain us.