Endless Facts, One Snippet at a Time
The Ozone Layer: How Chemistry Protects Life on Earth
- The ozone layer is a thin shield of O₃ molecules high in the stratosphere.
- It absorbs most of the sun’s harmful ultraviolet (UV) radiation before it reaches Earth.
- Without ozone, life on land would face dangerous levels of DNA-damaging UV rays.
- Ozone forms naturally when sunlight splits oxygen molecules into reactive atoms.
- These atoms bond with O₂ to create ozone, maintaining a protective balance.
- Human-made chemicals like CFCs once caused the ozone hole by breaking down O₃.
- International agreements, like the 1987 Montreal Protocol, phased out ozone-depleting substances.
- Since then, the ozone layer has been slowly recovering—a global success story in chemistry.
- Ozone at ground level, however, is a pollutant harmful to lungs and crops.
- Chemistry shows us how ozone can be both a vital protector above and a hazard below.