The breakdown of the ozone layer caused by chlorofluorocarbons is known as what?

• A. Ozone depletion
• B. Global warming
• C. Acid rain
• D. Eutrophication

Answer: (A)

Ozone depletion is the thinning of the stratospheric ozone layer caused by catalytic destruction from chlorine radicals released by chlorofluorocarbons. When CFCs rise into the stratosphere, UV light frees chlorine atoms that then participate in cycles that convert ozone into oxygen. For example, chlorine reacts with ozone to form ClO and O2, and then ClO can react with another oxygen atom to regenerate chlorine and produce more O2. The net result is fewer ozone molecules, i.e., depletion of the ozone layer. This is different from global warming (greenhouse gases trapping heat), acid rain (acidic precipitation from sulfur and nitrogen compounds), and eutrophication (nutrient overload in water bodies). So the breakdown of the ozone layer due to CFCs is ozone depletion.