[ben_w]

Indeed. I certainly hope that we don't get lots of those cranes lifting and lowering concrete blocks: we might, because they appear to be really cheap; but we shouldn't, because of how much CO2 is produced by making concrete.

Only way to be sure we don't get them is to invent something better.

I do like the aesthetics of hydroelectric dams: they also need concrete, though proportionally less.

I think some people are working on eco-friendly cements that would make for eco-friendly concrete; we certainly need that too, regardless of how we solve power production.