air
blaze
burning
chimneys
clogging
cloud
coal
contamination
contemporary
damage
day
ecology
economy
emissions
energy
environmental
factory
fire
flambeau
flame
fossil
fuel
gas
gasoline
global
hazard
heat
high
industrial
industry
inferno
natural
nature
oil
ozone
petroleum
pollution
power
price
recession
refinery
silhouette
sky
smog
torch
toxic
tube
urban
warming