>Low or zero emissions concrete

Feels like there's already options there.

https://www.popularmechanics.com/science/green-tech/a4078516...

https://cen.acs.org/materials/Chemex-goes-global-carbon-neut...

Although I'm betting it's better to just radically cut demand rather than try to invent a really good carbon-neutral/negative concrete. If we could sink a whole bunch of carbon into concrete though (significant carbon capture -> magic? -> concrete), that would be cool though.

That's a really uncomfortable fact with a lot of climate issues: it's way better to just not do the thing instead of trying to find a neutral/net-negative carbon process for the thing.