[jrochkind1]

The pellets are made from wood (rather than eg coal or other fossil fuels), the wood is just concentrated and processed to provide more calories of energy in a smaller more consistent package, to use wood byproducts like sawdust that don't start out easily burnable for fuel without processing, and to provide a perfectly consistent product that will always burn the same way with the same calories per gram.

If so, whatever is true of wood stoves is true of them, as far as carbon neutrality. It's the same resource. I guess burning wood is 'carbon neutral'? I guess, unlike fossil fuels, it is 'sustainable', in the sense that more can be grown?

It can still be awfully polluting. I think most modern pellet burning stoves actually emit less pollution than burning straight wood, because they burn more efficiently. But 'less' does not mean 'not'.

[mschuster91]

The problem is not greenhouse gases, it's the other pollutants that are caused by burning. Inadequate oxygen supply produces soot and carbon monoxide, and "trash wood" like e.g. wood that was used in train tracks or in buildings or in furniture is treated with all kinds of chemicals (flame retardants, oils and other residue from trains, plastics, paint) which turn very nasty when burned.