Agreed about the concrete. Fortunately there are efforts to replace concrete (in general) with other materials - some organic (fungi). > Plus, an unreinforced

Agreed about the concrete. Fortunately there are efforts to replace concrete (in general) with other materials - some organic (fungi). > Plus, an unreinforced concrete dome This is not a dome. It could conceivable be more population dense if/when they figure out how to magically get rebar into it :P. But that's not going to happen; and the real future benefits are likely going to be along the "working with nature" approach (where you use natural growing/expanding processes and direct them to suit your needs). In terms of future human survival, I'm surprised there's so little shown or seen regarding underground living. While obviously more complex due to the excavation and reinforcement processes, the survival and energy benefits are much higher. And with modern light gathering/direction tech, it doesn't have to be devoid of daylight.