Ozone Hole Discovered
British scientists discovered a massive hole in the ozone layer over Antarctica
May 16, 1985
A Hole in Our Protective Shield
In 1985, British scientists Joe Farman, Brian Gardiner, and Jonathan Shanklin published a paper reporting a dramatic thinning of the ozone layer above Antarctica. Their data, collected over several years at a remote research station, showed that ozone levels had dropped by more than 40 percent. The ozone layer, a band of gas in the stratosphere about 15 to 35 kilometers above Earth, absorbs most of the sun's harmful ultraviolet radiation. Without it, UV exposure would dramatically increase skin cancer rates and damage ecosystems.
What Was Causing It
Scientists quickly identified the culprit: chlorofluorocarbons, or CFCs. These chemicals were widely used in refrigerators, air conditioners, aerosol sprays, and foam packaging. When CFCs reached the stratosphere, ultraviolet radiation broke them apart, releasing chlorine atoms that destroyed ozone molecules in a chain reaction. One chlorine atom could destroy up to 100,000 ozone molecules. The discovery sent shockwaves through the scientific and political community.
International Action and Recovery
The response was remarkably fast for a global environmental problem. In 1987, nations signed the Montreal Protocol, agreeing to phase out CFC production. It became the first international treaty to achieve universal ratification — all 197 UN member nations signed it. By the 2000s, CFC levels in the atmosphere were declining. Scientists expect the ozone layer to fully recover to pre-1980 levels by around 2065. The ozone story is often cited as a model for international cooperation on environmental issues. Read about the Montreal Protocol for more on the global response.