Here's why:
* CFCs contain chlorine atoms: These atoms are the key to their ozone-depleting properties. When CFCs reach the stratosphere, UV radiation breaks them apart, releasing chlorine atoms.
* Chlorine atoms act as catalysts: They react with ozone molecules, breaking them down into oxygen molecules. This cycle can repeat many times, meaning a single chlorine atom can destroy thousands of ozone molecules.
Therefore, CFCs absorb UV radiation and break down ozone, not the other way around.
The fact that CFCs are good at absorbing UV radiation is what made them problematic for the environment. While they were originally lauded for their properties (non-flammable, non-toxic, and good refrigerants), their long-term effects on the ozone layer were eventually recognized. This led to their being banned globally by the Montreal Protocol.
