It is an option to use process co2 like cement. But you end up with a similar problem: You disincentivize carbon reductions in cement production. If we ever w

It is an option to use process co2 like cement. But you end up with a similar problem: You disincentivize carbon reductions in cement production. If we ever want to get serious about climate change then cement has to reduce its environmental impact. This is a hard problem (I am actually right now researching for an article about the topic), but all models with serious carbon reductions assume that on the medium term co2 emissions have to go down ~95%. As there are other things were carbon reduction is really hard cement can't use up all the remaining 5%. There are and were some startups trying to create greener cement, but all that went nowhere. The one that made most headlines - Novacem - went bankrupt and no longer exists.