Britannica
Sources used in this answer
How do chlorofluorocarbons reach the stratosphere after being released?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Ozone depletion
The Antarctic ozone hole reaches its maximum extent in October of each year. On October 7, 2021, when this image was captured, the Antarctic ozone hole spanned 24.8 million square km (9.6 million square miles).
Chlorofluorocarbons (CFCs) are chemically stable compounds that, once released into the lower atmosphere, do not easily break down. Because they are not reactive in the troposphere, they persist and are gradually transported upward by atmospheric circulation, eventually accumulating in the stratosphere.12
Unlike some other compounds that decompose in the lower atmosphere, CFCs can remain in the atmosphere for as long as 100 years. Once they reach the stratosphere, they are exposed to high levels of ultraviolet radiation. This radiation causes the CFC molecules to dissociate, releasing chlorine atoms that initiate the chemical process responsible for ozone depletion.21