air
atmosphere
blue
building
carbon
chemical
chimney
climate
coal
contamination
dioxide
ecology
electric
electrical
electricity
emission
energy
environment
environmental
exhaust
factory
fuel
fume
gas
generate
generator
global
high
industrial
industry
manufacturing
plant
pollute
pollution
power
production
sky
smog
smoke
smokestack
stack
station
steam
structure
technology
thermal
tower
toxic
warming
waste