air
architecture
blue
building
carbon
chimney
chimney stalk
clean
clear
construction
cylindric
cylindrical
danger
dioxide
ecological
ecology
electric
energy
environment
factory
flue
fume
fumes
funnel
global
industrial
industry
light
pipe
plant
pollution
power
red
refinery
sky
smog
smoke
smokestack
stack
stack furnace
stalk
tower
tube
vertical
warming