Satellite measurements conducted over Antarctica have unveiled a gigantic hole in the ozone layer. Termed an “ozone-depleted area,” this region spans 26 million square kilometers (10 million square miles), approximately three times the size of Brazil.
Ozone Layer and Ozone Hole
| Location | Stratosphere, approximately 10-30 km above Earth’s surface |
| Composition | Composed of ozone (O3) molecules. Unit of measurement: Dobsob Unit (DU) |
| Function | Acts as a protective shield, absorbing and blocking a significant portion of harmful ultraviolet (UV) radiation from the sun. |
| Importance | Essential for protecting life on Earth by preventing excessive UV radiation, which can harm living organisms and the environment. |
| Ozone-depleting Substances | Threatened by ODS like chlorofluorocarbons (CFCs), halons, and other synthetic compounds commonly used in refrigeration, air conditioning, and aerosol propellants. |
| Montreal Protocol | An international treaty adopted in 1987 to phase out the production and consumption of ODS, resulting in significant recovery of the ozone layer. |
| Current Status | The ozone layer is in the process of recovery due to the success of the Montreal Protocol. |
| Environmental Impact | Protects ecosystems, prevents skin cancer, cataracts, and other health issues in humans. |
| Additional Facts | The size of the ozone hole over Antarctica varies annually, opening in August and closing in November or December. Special winds caused by the Earth’s rotation create a unique climate over Antarctica, preventing mixing with surrounding air. When these winds subside, the hole closes. |
Potential Causes of the Giant Ozone Hole
- Volcanic Eruption in Tonga: According to scientific speculation, volcanic eruptions in Hunga Tonga, Tonga, between December 2022 and January 2023, may be the cause of this year’s large ozone hole. Through chemical interactions, the ozone layer was impacted by the emission of water vapor and other materials into the stratosphere by these eruptions.
- Human-Induced Ozone Holes: Scientists first observed substantial ozone depletion in the 1970s as a result of human activity, particularly the usage of chlorofluorocarbons (CFCs). The ozone layer was weakened by these compounds’ release of chlorine into the stratosphere.
- Effective Mitigation: The 1987 Montreal Protocol phased out chemicals that deplete the ozone layer in an effort to stop ozone depletion. Over time, the extent of ozone holes was successfully decreased by this international accord.
Ozone Depletion and Climate Change
- Not the Main Cause of Climate Change: Ozone depletion is not the main factor causing climate change in the world.
- Effect of Rising Temperatures: On the other hand, ozone holes might be impacted by rising global temperatures. Severe fires, like the ones that occurred in the southeast of Australia in 2020 and 2021, released smoke into the stratosphere, which may have contributed to the ozone hole.
- Changing Seasons: Ozone holes have the power to modify the course of the seasons by prolonging winter seasons by lengthening polar vortexes.
