What happens to CFCs when they enter the stratosphere?

When chlorofluorocarbons (CFCs) enter the stratosphere, they are broken down by ultraviolet (UV) light. This process is a crucial aspect of the atmospheric chemistry involving CFCs. In the stratosphere, UV radiation provides enough energy to break the chemical bonds of CFC molecules, releasing chlorine atoms. These chlorine atoms are highly reactive and can catalyze the destruction of ozone (O₃) molecules, leading to the depletion of the ozone layer, which is vital for blocking harmful UV radiation from reaching the Earth's surface.

The breakdown of CFCs is significant not only due to their contribution to ozone depletion but also because it highlights the environmental impact of these substances, which were commonly used in refrigeration and aerosol propellants. Understanding the fate of CFCs in the stratosphere is essential for developing regulations to mitigate their effects and protect the ozone layer.