If you cut down a tree, a new one will grow.  If you then go and cut
down the new tree, still another will grow.  And if you cut down that
tree, yet another will grow, only this one will be a mutation with
long, poisonous tentacles and revenge in its heart, and it will sit
there in the forest, cackling and making elaborate plans for when you
come back.

Wood heat is not new.  It dates back to a day millions of years ago,
when a group of cavemen were sitting around, watching dinosaurs rot.
Suddenly, lightning struck a nearby log and set it on fire.  One of the
cavemen stared at the fire for a few minutes, then said: "Hey!  Wood
heat!".  The other cavemen, who did not understand English, immediately
beat him to death with stones.  But the key discovery had been made, 
and from that day forward, the cavemen had all the heat they needed,
although their insurance rates went way up.
               -- Dave Barry, "Postpetroleum Guzzler"