[vidarh]

I ended up in an argument with local "environmentalists" exactly over this (in quotes, because I think being opposed to high density is not very environmentalist at all):

They complained about new highrises near my local train station. I pointed out to them that those highrises would take up ~2,000 m^2 but provide housing for as many as one of the nearest local roads, that with the sidewalks, houses and gardens, many of which are paved over or mostly decking, takes up ~40,000 m^2.

As such, if they wanted more green spaces the better stance would be to argue for replacement rather than denying planning: E.g. make developers commit to buying up more low density housing and demolish a proportion of it and replace it with parkland or rewild it. The overall societal effect of not increasing housing supply as much would be a negative (and so there may well be needs for government incentives), but increased green spaces would be a positive. And if it reduced overall resistance to more high density construction to explicitly link density to replacement, I think it'd be worth it. E.g. award construction proposals with "points" in favour for whatever amount of existing construction they replace with parkland or nature that causes planning rules to strongly favour projects that increase density.

But said "environmentalists" seemed dead set on seeing bigger buildings as inherently bad without engaging with the point that absent getting rid of people, creating more space for nature means making people take up less space, and that means higher density.

To me arguing for high density is an essential part of environmentalism.