1) Does this require that the atmosphere forever stay at the current CO2 concentration, or will it continue to work well if we manage to clean the atmosphere properly?

2) Does this also pave the way for more permanent CO2 cleanup of the atmosphere?

3) Since they have really economical extraction of H2, could they just ramp down the CO2 extraction and instead buy in CO2 emitted from industrial processes? I'm not sure if this is an interesting suggestion or not, since the CO2 goes into the atmosphere either way, but at least we would be getting two usages out of it.