air
blue
carbon
chemical
chimney
climate
condensation
damage
danger
day
dioxide
dirty
effect
energy
environment
environmental
exhaust
factory
fossil
fumes
gas
global
greenhouse
heat
heavy
horizontal
impact
industrial
industry
manufacturing
nature
nobody
outdoors
pipe
polluting
pollution
power
refinery
sky
smog
smoke
smokestack
stack
steam
technology
tower
toxic
warming
white
wind