air
atmosphere
carbon
change
chemical
chimney
climate
cloud
coal
cooling
crisis
danger
dioxide
dirty
dust
ecology
emission
energy
environment
environmental
exhaust
factory
fuel
fume
gas
generation
global
industrial
manufacturing
nuclear
ozone
pipe
plant
poison
pollute
pollution
power
production
sky
smog
smoke
smokestack
station
steam
technology
tower
toxic
vapor
warming