What effect do chlorofluorocarbons (CFCs) have on the ozone layer?

Chlorofluorocarbons (CFCs) deplete the ozone layer primarily due to their chemical composition and how they interact with ultraviolet (UV) radiation in the atmosphere. When CFCs are released into the atmosphere, they eventually rise to the stratosphere, where they are broken down by UV radiation, releasing chlorine atoms. These chlorine atoms are highly reactive and can catalyze the breakdown of ozone molecules (O3) into oxygen molecules (O2).

The depletion of the ozone layer is significant because the ozone layer serves as a protective shield for the Earth, absorbing the majority of the Sun's harmful ultraviolet radiation. The loss of ozone contributes to increased levels of UV radiation reaching the Earth's surface, which can lead to adverse effects like increased skin cancers, cataracts, and harm to ecosystems.

In contrast, other options do not accurately represent the impact of CFCs on the ozone layer. They do not have any beneficial effect on its function, nor do they repair it, and stating they have no effect overlooks the substantial scientific evidence demonstrating their harmful impact.