against
air
blue
building
carbon
chemical
chimney
clear
climate
cloud
construction
contamination
day
dioxide
ecology
emission
energy
environment
environmental
exhaust
factory
fuel
fume
gas
generation
global
harmful
industrial
industry
manufacturing
oil
pipe
plant
pollution
power
sky
smoke
smokestack
stack
stacks
steam
sunny
sunshine
tower
vapor
warming
waste
white