Eugenics? What eugenics? There is no mention of eugenics in this research paper. 
Just the eco-fascist narrative that climate change isn't caused by capitalism, but by too many people consuming resources faster than they can be replenished. I'm sure that's not a dangerous idea useful to anyone or anything. 
It's obvious no serious discussion can be had here. 
/r/collapse used to be mostly left leaning, if a bit lib and doomer sometimes. At some point, it got an influx of right wing reactionaries, and it was pretty much over then. They used to heavily police eugenicist rhetoric, and it mostly served as a climate change space that wasn’t just techno hopium about how carbon capture and nuclear power were going to save the world.
i get the doomer stuff. my theory is that the majority are super-depressed libs, and see any collective left action as too impossible/exhausting. so the few that aren't just of the "i will end my life the instant the power goes out" are just hoping the eco-fash take care of things for them
i mean, they're probably white and comfortable and figure they will survive purges restricted to the borders and the Global South