Related Clues:
- Layer to worry about
- *Triatomic gas
- Like an egregious plot hole
- With love three can affect the atmosphere
- One of the greenhouse gases
- Stratosphere substance
- Colourless gas, O3
- 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
- Gas that screens ultraviolet radiation
- Gas in the stratosphere
- A gas; threatened layer in air
- Healthy air of one putting on a little weight
- A poisonous gas; seaside air