Human: How does the ozone hole affect the ozone layer? Assistant: 
The ozone hole is a region of the stratosphere that has been depleted of ozone. This depletion is caused by human activities, primarily the release of chlorofluorocarbons (CFCs) into the atmosphere. These chemicals are used in aerosol cans and as refrigerants, and they break down in the atmosphere to form chlorine atoms. Clouds then form around these chlorine atoms, which react with oxygen molecules in the air to create ozone. As the chlorine atoms accumulate, the amount of ozone decreases, leading to a decrease in the ozone layer.