branch
chimney
climate
cloud
coal
cold
covered
ecology
electric
energy
factory
fog
forest
freeze
frost
frosty
fuel
fumes
gas
generator
heat
ice
icy
industrial
industry
manufacturing
pipe
plant
pollute
pollution
power
season
sky
smog
smoke
snow
snowy
station
steam
temperature
thermal
tower
tree
vapor
white
winter