What is a significant environmental concern regarding CFCs?

Chlorofluorocarbons (CFCs) are primarily known for their role in depleting the ozone layer, which is a critical component of Earth’s atmosphere that protects life from harmful ultraviolet (UV) radiation. The ozone layer absorbs the majority of the sun’s harmful UV rays, and when CFCs are released into the atmosphere, they eventually rise to the stratosphere. There, they are broken down by UV radiation, releasing chlorine atoms that catalyze the destruction of ozone molecules.

This depletion leads to increased levels of UV radiation reaching the Earth's surface, which can cause a range of detrimental effects, including heightened incidences of skin cancer, cataracts, and other health problems in humans, as well as adverse impacts on ecological systems, including aquatic life that is sensitive to UV exposure.

While CFCs may have indirect effects on global warming and other environmental issues, their most significant and direct impact is on the ozone layer, making this the key environmental concern related to their use and emission.