As best as I can tell, two of your links talk about development of cement that could sequester CO2 (just like the article we're commenting on mentions too). The

As best as I can tell, two of your links talk about development of cement that could sequester CO2 (just like the article we're commenting on mentions too). The problem is that it's too expensive relative to regular cement. One of your links concludes "we don't know" how much CO2 regular cement sequesters.