No, I'm not suggesting that everyone use wood! It is impractical at best for many. However, there is a lot of 'waste' wood out there that is basically free heat with no demand on timber stocks. Using it also means it won't take up space in a landfill site! The challenge is accessing it in an efficient manner, but if you can make it work, it is great. I picked up ~400 kg of kiln dried oak yesterday, loaded by forklift in a single bundle onto my trailer. I got a similar bundle on Tuesday, and I'm going back for another today. Now that represents about 2 weeks of heat for our place, give or take 3-4 days depending on a few variables, but then we have a huge place to heat! That might last half the winter for some places.
Modern high efficiency wood stoves burn the wood very cleanly, and I think such a stove burning kiln dried wood would not produce much by way of emissions. More than natural gas? Likely. But when you consider how electricity is generated, it would beat electricity for sure. And, given the costs, economically and environmentally, of gas pipeline construction, operation, and maintenance, I think wood wouldn't be that bad in a full comparision. Plus, burning wood is carbon neutral- no carbon being removed from the ground and released into the atmosphere.
Unfortunately, our wood furnace is NOT high efficiency! I have since learned about some inherent design flaws that all of them have. I am researching some improvements, however, and may be able to almost double the combustion efficiency if I'm willing to do a bit of welding and void my warranty!
We also get to burn the non-recycleable 'soiled' newspapers from our animal cages, as well as the aspen and cypress mulches (though these often go into the compost). Again, less landfill!
So overall, I think we're on the plus side on the ecological scale. Not to mention, we can heat the whole place by running one solenoid valve, 2 1/25th HP pumps, and 3 fans (house, herp room, classroom). Not much draw on a generator in the event of a power outage, and eventually I can run off photovoltaic. Like I said, though, not practical for everyone, but it does work exceedingly well for our situation.
Congrats on switching your fireplace- regular fireplaces are virtually useless, and extremely inefficient at best, for heating a house.