Referring Clues

• Fresh air, slangily
• Kind of layer
• Thunderstorm product
• Earth protector
• What CFC's deplete
• Ultraviolet Index factor
• Subject of environmentalist study
• Composition of an endangered layer
• Kind of hole
• Odorous oxygen
• Contents of a sensitive layer
• Layer with a hole in it
• Ray blocker
• Form of oxygen
• Ultraviolet ray blocker
• Thunderstorm residue
• Earth's ___ layer
• Gas in a layer
• O3
• Atmosphere layer
• Kind of layer protecting the earth
• Ultraviolet light filter
• Ultraviolet filter
• Gas with a penetrating odor
• A high flier may fly in it
• Ultraviolet blocker
• Radiation reducer
• Layer with a "hole"
• Oxygen with a weak chlorine odor
• Fragile atmosphere layer
• With 26-Down, environmentalist's concern
• Ecologist's concern
• 22-mile-high layer
• Layer that screens ultraviolet rays
• Upper atmosphere layer
• Upper atmosphere gas
• Damaged layer
• Ultraviolet ray absorber
• Blue gas
• Layer of concern to ecologists
• Stratosphere substance
• Threatened atmosphere layer
• Endangered layer
• Upper atmospheric layer
• Triatomic oxygen
• Layer discussed in "An Inconvenient Truth"
• Dwindling gas in the stratosphere
• Stratosphere gas
• Endangered atmospheric layer
• Atmospheric gas
• Hole site
• Form of oxygen with a sharp odor
• Corrosive substance
• Diminishing layer
• Layer with a hole
• Allotrope of oxygen
• Absorber of ultraviolet radiation
• Triatomic greenhouse gas
• Bluish gas
• Allotrope of element #8
• Triatomic form of element #8
• ___ hole
• Photochemical smog component
• Layer of concern
• Atmospheric layer
• Important layer
• Electrical storm byproduct
• ___ hole
• Protective layer
• Layer to be concerned about
• Layer that absorbs ultraviolet rays
• Imperiled layer
• Oxygen allotrope
• Water sterilizer
• Ultraviolet-ray blocker
• Threatened layer
• ___ layer
• UV blocker
• Stratospheric gas
• Layer with a "hole"
• Certain atmospheric layer
• Certain atmospheric gas
• Important type of layer
• Sensitive layer
• Ultraviolet radiation absorber
• Layer up high
• Atmospheric layer of note
• Eco-worry
• Thunderstorm byproduct
• Much-discussed layer
• Kind of hole or layer
• Atmospheric concern
• Environmentalists' concern
• Bleaching agent
• Greenhouse gas
• UV ray absorber
• Refreshing air
• Gas that both protects and pollutes
• Radiation-reducing layer
• Triatomic molecule
• Trioxygen molecule
• It protects everyone
• It protects everybody
• Triatomic pollutant
• Shrinking layer
• ___ layer
• Pungent gas
• Depleted layer
• Pale blue gas
• Swimming-pool sanitizer
• Atmospheric layer with a "hole" in it
• Gas made by lightning
• With a near-homonym of 16-Across, a holey protector
• Holey protector
• A holey protector
• Pure air
• UV stopper
• Oxygen variety
• Fresh air
• Thinning layer
• Ultraviolet filterer
• Makeup of a protective layer
• Contents of a newsworthy layer
• Protective layer makeup
• Earth-surrounding layer
• Oxygen form
• Atmosphere component
• Protection around the world?
• ___ layer (upper atmosphere part)
• Dog days pollutant
• O-O-O
• Stratosphere layer
• Layer that filters out UV rays
• Lightning strike by-product
• With 40-Down, depleted atmospheric region
• A layer with a hole
• Spa sanitizer
• Layer with holes
• Layer to worry about
• One of the greenhouse gases
• Layer with "holes" in it
• Triatomic oxygen molecule
• Triatomic gas in a thinning layer ... and, symbolically, what appears in this puzzle's four longest answers
• 03
• It's a gas
• Gas in the stratosphere
• Thinning atmospheric layer
• Form of 10-Down
• Lightning byproduct
• Layer in the stratosphere
• UV light blocker
• Part of the atmosphere depleted by CFCs
• Lightning by-product
• Holey layer
• Layer in global warming discussions
• It covers the globe
• Bluish 45-Down
• Atmosphere protector
• Layer with a 'hole' in it
• Trioxygen
• A greenhouse gas
• Smog component
• Worry of stratospheric proportions
• Stratospheric layer
• Much-talked-about layer
• UV ray-blocking gas
• Depleted atmospheric layer
• ___ hole (modern worry)
• Layer that reduces radiation
• Absorber of UV rays
• Gaseous oxidant
• Substance in a stratospheric layer
• Layer that blocks the sun's rays
• Some bozo needing gas
• Fresh bracing air
• Ace Frehley song about a layer?
• Form of oxygen, O₃
• Gas forming screen against ultraviolet radiation in the stratosphere
• Sea air
• Gas, about 28 gm?
• Some atmosphere at wizard's postcode?
• Something in the air makes one put on weight? On the contrary
• Sea air adds a little weight to one
• Sea air (found in layer?)
• Shield against radiation
• One's put on weight - it's something in the air
• Australia's a gas!
• With love_threecan affect the atmosphere
• Less common form of oxygen
• Colourless gas
• Gas in a stratospheric layer
• Individual's underweight: seaside atmosphere needed
• Australian one needing invigorating air
• Protective layer for District and Circle? Vice versa
• Gas ring on range
• (Depleted) layer of gas
• Gas forming protective layer
• Bracing air in Ohio district
• Gas formed from oxygen
• Snooze - head drops - rest could be a tonic
• Antipodean individual seeking bit of 22
• Essential atmospheric layer
• Atmospheric layer that absorbs ultraviolet rays
• *Triatomic gas
• Condensed oxygen
• Endangered atmosphere layer
• Gas obtainable from Australia only
• Lightweight single layer
• Australian individual gets sea air
• Invigorating air of the seaside
• Australia has ace sea air!
• Form of atmospheric oxygen
• Bracing air of old; now seen as potentially toxic
• Colourless gas soluble in alkalis and cold water
• Ring precinct for gas
• Bracing air round region
• Invigorating air round area
• Invigorating air round region
• Invigorating air in heart of blowy region
• Clean bracing air round region
• Former London dialing code's a gas
• 13 1 is in the air
• Economic region's currency traded for no gas
• Large island reduced by a gas
• Cardinal from Brisbane perhaps, a gas
• Gas with a pungent odor
• Layer of the upper atmosphere
• Element not in usual form - wrongly ordered an ounce
• Atmospheric screen
• Gas in an atmospheric layer
• Gas in a protective layer
• Gas - over one ounce
• Overhead concern?
• Protective atmospheric layer
• Air supply
• Ultraviolet absorber
• Another name for O3 (as appropriate to 17-, 25-, 44- and 58-Across?)
• Contents of a big layer
• Atmospheric gas of concern to Gore
• As gases go, a weighty one?
• Atmospheric layer of oxygen
• Critical layer
• Trioxygen alias
• It's made of three oxygen atoms
• Pungent, pale-blue gas
• ___ layer (stratosphere part)
• Bracing sea air
• Makeup of a layer in the stratosphere
• Gas that puts weight on a person
• Layer that absorbs ultraviolet radiation
• Layer that blocks ultraviolet rays
• UV-blocking molecule
• Atmospheric oxidant
• Gas
• Smog ingredient
• Depleting in the sky
• Stuff in a stratospheric layer
• Circle the area with the bracing air
• ___ layer (part of the stratosphere)
• Layer way up high
• Smog element
• Globe coverer
• ___-friendly (ecolabel)
• Vital part of the stratosphere's protective layer
• Stratosphere layer protected by the Montreal Protocol
• Stratosphere layer with a "hole"
• What offers worldwide protection?
• Global protection
• UV-blocking gas
• Atmospheric layer with holes
• Stratospheric shield
• Layer wrapping Earth
• Absorber of UV light