Burning wood for heat creates a lot of pollution but so does burning natural gas and electricity for heat.
All wood stoves should put out some smoke when first started but wood stoves shouldn't put out smoke all the time.
So wood stoves are pretty green to heat with. And in the event of a power failure you can still have heat in the winter so long as you have a good wood supply.
Wood is a renewable resource so it's a lot better to heat with wood than it is to heat with natural gas or electricity or other non renewable resources.