The Ozone Layer and Hole

The Earth's ozone layer, located in the stratosphere, absorbs harmful UVB rays from the Sun, protecting life on Earth. In the 1980s, scientists discovered significant ozone depletion over Antarctica and the Arctic, linked to chlorofluorocarbons (CFCs). These stable industrial chemicals release chlorine when exposed to UV light, which then breaks down ozone. The Montreal Protocol was established to phase out CFCs, aiming for ozone recovery by 2050.

What percentage of the Sun's ultraviolet-B rays does the ozone layer absorb?

• 50% to 60%

• 70% to 80%

• 100%

• 93% to 99%

Where was the extreme depletion of atmospheric ozone first recorded in the 1980s?

• Above Antarctica

• Above the Arctic

• Over the equator

• In the Northern Hemisphere

What family of industrial chemicals was found to be damaging the ozone layer?

• Nitrogen oxides

• Chlorofluorocarbons

• Sulfur compounds

• Hydrocarbons

What role do polar stratospheric clouds play in ozone depletion?

• They reflect UV rays back into space

• They increase the temperature of the stratosphere

• They provide a surface for chemical reactions

• They block sunlight from reaching the Earth

What is the purpose of the Montreal Protocol?

• To study the effects of global warming

• To monitor UV radiation levels

• To phase out the use of harmful chemicals

• To increase the production of CFCs