Doomerism is observing that first order effect and trying to assert that we should change behavior at a societal level

I don’t think this is as universal a definition of ”doomer” as you think. To pick up on one of your examples I’ve seen people being called ”AI doomers” for holding every position between ”all of these huge investments might not pay off” to ”it will exterminate mankind and make paperclips out of the universe”. Where is the line for Real Doomerism? Be careful when you draw it lest you end up on the wrong side of history.

I think your point about mankind’s adaptability is fair but you’re working with a definition of the word ”doomer” that makes it extremely easy for you to prove your point. ”Every time the end of the world has been predicted it has been wrong because we’re still living in a world” is true but not a particularly clever or interesting argument.

Also you need to chill with the ”YOU’RE using as a doomer” and ”YOU fundamentally cannot grasp” stuff. Lol, ”buddy”, you have literally no idea who’s on the other side of that screen of yours or what they can ”fundamentally grasp”.