Do you know how many environmental problems Dwarves cause by their unregulated mining?
If I remember, they released a Balrog; a demon of both shadow and flame. Imagine the CO2 emissions of that thing. Few things can match the environmental damage to Middle Earth done by Mount Doom, however, which frequently erupted at Sauron’s command. It was almost as bad as China.
I would worry about the treachery of the DINOs(Dead In Name Only)
Otherwise known as "the Dead Men of Dunharrow"
Beware the Path of the Dead, Aragorn!