They still need air i don't remember wrongly?
Well I'm not sure of this... the beard could shelter quite a big volume of air
Beofre, I was just saying that I doubt there'll be any global effect because of the 2000 dwarves all around the world.
And that dwarves as we know them won't pour radioactive wastes in the river down from their fortress (although I've always seen poisoning a river an excellent way of dealing with that goblin fortress down the brook).
I saw, like everyone, forests disappear during worldgen next to fortresses, and I don't doubt dwarves CAN erase a small forest. The problem was with how dwarves would handle it.
Are DF dwarves rock-lovers who despise vegetal beings, plants and trees? Then they shouldn't get any bad thought at the sight of a no-man's-land where there was once a forest.
Or do they see trees as a need for their fortresses, and therefor try not to use too many? Deforestation would be annoying but that's all.
Or is it left as a personal thing, that everyone deals with according to his religion?
On the death by CO, dwarves have survived so far underground, and carbon monoxyde has always been a problem for humans, yet dwarves may be different than humans. CO as more affinity with hemoglobine than O2 in the human blood, but dwarven blood may be sligthly different.
Not saying it is, but it could be. Not saying it shouldn't have any effect, but they would sure get better faster than humans.
I want to have ventilation in too, I'm just chatting.