Mention one environmental impact of refrigerants.

The depletion of the ozone layer is a significant environmental impact caused by certain refrigerants, particularly chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). These substances, once commonly used in refrigeration and air conditioning systems, can release chlorine atoms when they reach the stratosphere. This process contributes to the breakdown of ozone molecules, leading to a thinner ozone layer. The ozone layer plays a crucial role in protecting life on Earth by absorbing the majority of the sun's harmful ultraviolet (UV) radiation. When the ozone layer is depleted, increased levels of UV radiation can reach the Earth's surface, resulting in higher instances of skin cancer, cataracts, and negative effects on various ecosystems.

In contrast, options that suggest improved air quality, increased plant growth, or a reduction of greenhouse gases do not accurately reflect the impact of refrigerants, as many traditional refrigerants have primarily negative effects on the environment.