We are so massively far away from being able to do that, it's not worth worrying about. Especially since active carbon capture methods can easily be switched off long before we approached any "dangerous" level.

You can stop making new olivine beaches. The scale necessary means it would be a long, slow process.

The beaches will continue absorbing CO₂ long after you stop making them. I think this is probably a manageable problem but it's important to recognize that, as with emitting the CO₂ in the first place, the feedback can be a long time in coming, so there is a risk of the system running out of control.

We already have fairly functional knobs for increasing carbon emissions.

Well in that case the combustion engine will earn a second golden age. :-)