[ordu]

Hmm... If we are removing CO2 at that rate from some place, then the concentration of CO2 in local atmosphere will drop. It will create a gradient so CO2 will start moving toward us, but what the maximum rate of CO2 diffusion? Wouldn't it impair our ability to miniaturize the ocean filled with diatoms as a CO2 absorber?

Though probably one can try to create an artificial wind, blowing CO2-free air away so CO2 could move quickly into the freed space.

[delecti]

There are a lot of prevailing winds around the world. You'd have to go out of your way to find somewhere still enough that local concentration could drop, rather than just creating a very slight CO2 "shadow" downwind.