When we get the political consensus to put a price on atmospheric carbon, it will give a subsidy to anyone who can make a solid material out of carbon. What wil

When we get the political consensus to put a price on atmospheric carbon, it will give a subsidy to anyone who can make a solid material out of carbon. What will be the most economical way to get those subsidies? I don't think it will be making carbon nanotubes. That requires an extremely pure source of carbon. I think the biggest application will be construction materials: Mine CaO, use atmospheric CO2 to convert it to CaCO3 this use that as feeder stock for making limestone-like and marble-like construction materials. These could be premium materials -- I could easily see Salesforce paying a premium to cover the floors of Salesforce tower in 'reclaimed atmospheric marble' to advertise their green creds -- or a down market material -- just mix it in to drywall to get the CO2 credits. Either way, this process would be much less fussy about the purity of the CO2 source.