air
atmosphere
background
billow
billowing
carbon
chemical
chimney
climate
cloud
co2
contamination
cooling
damage
day
daytime
dioxide
electricity
energy
environment
environmental
factory
fumes
gas
gasses
global
greenhouse
harmful
industrial
industry
manufacturing
nature
outdoor
ozone
pipe
plant
pollution
power
sky
smog
smoke
smokestack
station
steam
steel
sun
tower
toxic
warming
white