The fires don't accelerate it much. That wood and shrub would either burn or rot down the line and release methane and co2 anyway. Forests don't sequester much at all despite what people seem to believe.

Consequentially running a fireplace is a lot more climate neutral than driving a car, taking a flight, utilising the myriads of high carbon footprint goods or having a gas heater or so.

On the other hand the bogs that we're losing (and kelp forests) are a lot better at sequestring co2 but they're small. Permafrost will also actually accelerate stuff since....well it __was__ permanently forsty.