2 problems with that approach IMHO: * That tax would have to be so high to fully pay for the environmental damages mining is causing, that it would make mining

2 problems with that approach IMHO: * That tax would have to be so high to fully pay for the environmental damages mining is causing, that it would make mining not economically viable anyway. So might as well save yourself from burning public funds trying to find ways to legislate and enforce that tax (no secret that crypto people tend to not declare a lot of their coins). * Allowing new/more emissions to happen now counting on the fact that we will just take that carbon out of the atmosphere later on is exactly the wrong thing to do. We will already need gigantic monetary and technological investments to make that technology able to pump out any significant amount of CO2 assuming we do all the right things toward decarbonization until this is possible, so we don't really need to shoot ourselves in our only remaining foot by just adding more CO2 to be removed. Not emitting one ton of CO2 today is much much more valuable than pumping one ton out later on, just because of the massive amount of energy needed to pump it out. So I think banning is absolutely the right choice.