air
atmosphere
building
carbon
chemical
chimney
clouds
co2
contamination
damage
danger
dioxide
dirty
ecology
emission
emissions
energy
environment
environmental
exhaust
factory
fuel
fume
fumes
gas
global
greenhouse
industrial
industry
manufacturing
oil
pipe
plant
pollute
polluting
pollution
power
refinery
sky
smog
smoke
smokestack
stack
steam
technology
tower
toxic
vapor
warming
waste