The Ozone Layer Crisis and its Resolution

Introduction

1980s Problem: Expanding hole in the ozone layer.
Ozone Layer Role: Absorbs 98% of the Sun's UV radiation, protecting life on Earth.

CFCs: Chlorofluorocarbons, chemicals disrupting ozone balance.
- Developed in the 1920s as non-flammable, non-toxic coolants by US corporations.
- Used widely in everyday items; became a huge industry.
Molina and Rowland (1970s): Discovered CFCs broke down in the stratosphere and released chlorine atoms that destroyed ozone.
- Chlorine atoms can destroy thousands of ozone molecules.

Initial Estimates: CFCs could reduce ozone by 7% in 60 years.
Accelerated Ozone Loss: By 1985, significant depletion observed, especially in Antarctica.
- Antarctic clouds and cold temperatures accelerated loss.
- Satellite data confirmed CFCs as the cause.
Public Awareness: NASA visualizations highlighted the issue, raising global concern.
Potential Consequences:
- Increased skin cancer rates.
- Impaired photosynthesis in plants, affecting agriculture and ecosystems.

Political Challenges: Debate over immediate economic impacts vs. long-term environmental risks.
Allies for Ban: Unlikely support from US President Ronald Reagan and UK Prime Minister Margaret Thatcher.
- Both saw the need for action despite usual opposition to regulation.
Montreal Protocol (1987): International treaty to phase out CFCs.
- Supported by US, UK, Canada, Norway, Sweden, and Finland.
- Fund established to help Global South countries transition to alternatives.
- Universally ratified - unique in history.

Recognition: Molina, Rowland, and Crutzen awarded the Nobel Prize in Chemistry (1995).
Ozone Recovery: Hole shrinking, expected disappearance by 2070.
New Issues with HFCs: Replacement chemicals, hydrofluorocarbons, also potent greenhouse gases.
- Kigali Amendment (2016): Calls for 85% reduction of HFCs by 2047.