> You can predict that not emitting CO2 will cost less than emitting CO2 and then recapturing it, because it's the second law of thermodynamics. I'm not sure t

> You can predict that not emitting CO2 will cost less than emitting CO2 and then recapturing it, because it's the second law of thermodynamics. I'm not sure that's true, in two senses. Even if the _energy_ cost is higher, the _monetary_ cost may be lower as emissions and capture don't need to be in the same place. It may be cheaper for example to just burn some petrol to cover long distances where there's less infrastructure and instead capture an equivalent amount of CO2 using energy from solar panels somewhere sunny. I'm not certain the energy cost must be higher due to thermodynamics. If you were taking CO2 and water and recombining them to get back nat gas and oxygen then sure. But what if you're taking the CO2 and doing something else with it? If I'm thinking about this right the bond energy in CO2 is a little lower than the overall energy released. Of course things come down then to efficiencies but I don't think there's a thermodynamics point here.