Question

In 1985, a researcher in Antarctica noticed that ozone levels in the atmosphere seemed to be as much as 35 percent lower than the average values during the 1960s. Satellite images taken over the South Pole revealed that the ozone concentration was unexpectedly lower over Antarctica than elsewhere in the Earth’s atmosphere. It was as if an “ozone eater” were causing a mysterious zone of below-normal concentration, an area that researchers called the ozone hole. Which human activities are thought to be responsible for creating this ozone hole in the upper atmosphere? (SC.912.L.17.20)
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1 point
increasing the human population and cutting down forests
burning fossil fuels and the related increase in atmospheric CO2
burning sulfur-rich coal and increasing levels of greenhouse gases
producing and releasing chemicals called chlorofluorocarbons (CFCs)

Answer 1

The human activities thought to be responsible for creating the ozone hole in the upper atmosphere are the production and release of chemicals called chlorofluorocarbons (CFCs). CFCs were commonly used in refrigerants, aerosol sprays, and foam-blowing agents. When released into the atmosphere, CFCs eventually rise to the stratosphere, where they break down ozone molecules, leading to the depletion of the ozone layer, particularly over Antarctica.