environmental
air
asthma
atmosphere
atmospheric
carbon
chimney
clouds
concern
damage
dark
dioxide
dirty
emissions
emit
emitting
environment
factory
fossil
fuel
fume
fumes
global
gloomy
gray
grey
grunge
grungy
harm
haze
industrial
industry
overcast
plant
pollutant
pollution
problem
refinery
sky
smog
smoke
smokestack
smokestacks
somber
sombre
stack
substance
technology
threat
toxic
warming