Ozone Layer Depletion Quiz

The Ozone Layer Problem

• In the 1980s, a rapidly expanding hole in the ozone layer was discovered, threatening life on Earth.
• The ozone layer protects plant and animal DNA from the Sun's UV radiation, absorbing about 98% of it.

CFCs and Ozone Depletion

• Chlorofluorocarbons (CFCs) were developed in the 1920s as coolants for refrigerators and soon became widely used in various products.
• CFCs were non-flammable, non-toxic, and made great propellants, foaming agents, and fire-retardants.
• In the stratosphere, CFCs are broken apart by UV light, releasing chlorine atoms that react with ozone and destroy it.
• A single chlorine atom can destroy thousands of ozone molecules before forming a stable molecule.

The Discovery and Response

• In the 1970s, chemists Mario Molina and Sherwood Rowland demonstrated the harmful effects of CFCs on the ozone layer.
• CFC producers initially disputed the findings, but by 1985, the rapid ozone depletion over Antarctica was clear.
• NASA visualizations and satellite data revealed the extent of the losses, and chemical tests confirmed CFCs as the cause.

The Consequences and Solution

• If ozone depletion continued, rates of skin cancer would increase, and global agricultural production would plummet.
• US President Ronald Reagan and UK Prime Minister Margaret Thatcher, despite their initial reluctance, recognized the need for immediate action and led the international effort to ban CFCs.
• The Montreal Protocol, signed in 1987, required the phasing out of CFCs and created a fund to assist developing countries.
• The treaty was ratified by every country on Earth, and the use of CFCs declined, leading to the ozone hole shrinking.

The Legacy and Remaining Challenges

• The Montreal Protocol serves as a model for global cooperation in combating climate change.
• The alternatives to CFCs, hydrofluorocarbons (HFCs), are also potent greenhouse gases and contribute to climate change.
• The Kigali Amendment, added to the Montreal Protocol in 2016, aims to reduce global HFCs by 85% by 2047.
• The Montreal Protocol's success is a reminder of the need for decisive global cooperation to combat climate change.

The Ozone Layer Problem

• The ozone layer absorbs about 98% of the Sun's UV radiation, protecting plant and animal DNA.
• A rapidly expanding hole in the ozone layer was discovered in the 1980s, threatening life on Earth.

CFCs and Ozone Depletion

• Chlorofluorocarbons (CFCs) were developed in the 1920s as coolants for refrigerators and later used in various products.
• CFCs were non-flammable, non-toxic, and made great propellants, foaming agents, and fire-retardants.
• In the stratosphere, CFCs are broken apart by UV light, releasing chlorine atoms that destroy ozone molecules.
• A single chlorine atom can destroy thousands of ozone molecules before forming a stable molecule.

The Discovery and Response

• Chemists Mario Molina and Sherwood Rowland demonstrated the harmful effects of CFCs on the ozone layer in the 1970s.
• By 1985, the rapid ozone depletion over Antarctica was clear, and chemical tests confirmed CFCs as the cause.
• NASA visualizations and satellite data revealed the extent of the ozone layer losses.

The Consequences and Solution

• If ozone depletion continued, rates of skin cancer would increase, and global agricultural production would plummet.
• The Montreal Protocol, signed in 1987, required the phasing out of CFCs and created a fund to assist developing countries.
• US President Ronald Reagan and UK Prime Minister Margaret Thatcher led the international effort to ban CFCs.

The Legacy and Remaining Challenges

• The Montreal Protocol serves as a model for global cooperation in combating climate change.
• Hydrofluorocarbons (HFCs), alternatives to CFCs, are also potent greenhouse gases and contribute to climate change.
• The Kigali Amendment, added to the Montreal Protocol in 2016, aims to reduce global HFCs by 85% by 2047.
• The Montreal Protocol's success highlights the need for decisive global cooperation to combat climate change.