[imtringued]

Yes, if we wanted to actually solve the problem, then the CO2 tax should be set at the level of the cheapest process that lets us capture CO2.

However, you must understand that even the existence of a CO2, even with a CO2 dividend is controversial, not because it doesn't work but rather people of lack of awareness and general disdain for taxes.

So having a low CO2 tax is still better than nothing.

Also, you might need to incrementally increase CO2 prices over time to make it possible for businesses to plan ahead for the next three decades. If you abruptly increase the tax you might ruin business decisions made decades ago which threatens economic stability.