> My experience on a 2009 carbon capture plant design was that approx $100 per tonne of CO2 was the lowest carbon price that would really make carbon sequestration highly attractive and widespread.

Is there a market for captured carbon? I understand there is a small market for industrial process and carbonated water, but are there people buying long-term capture in large enough quantities to make an impact?

Anyway, I don't think the price matters on that scale. Once we decarbonize electricity, I think it will be governments and non-profits that will do most of the carbon capture (unless there exists a large market for my previous question), and for those a lower price only means a higher rate of growth, not the difference between viable or non-viable.