World Ozone day is held on September 16th every year to mark the day back in 1987 when the Montreal Protocol was signed. As a result, a number of special events such as talks and seminars are held in the Canadian city of Montreal on this day.
This day has been celebrated since 1994 and was established by United Nations General Assembly. The day is mainly intended to spread awareness of the depletion of the ozone layer and search for the solution to preserve it.
Depletion of Stratospheric Ozone is mainly caused by:
- Emissions -Halogen source gases are emitted at Earth's surface by human activities and natural processes.
- Accumulation- Halogen source gases accumulate in the atmosphere and are globally distributed throughout the lower atmosphere by winds and other air motions
- Transport- Halogen source gases are transported to the stratosphere by air motion.
- Conversion- Most halogen source gases are converted in the stratosphere to reactive halogen gases in chemical reactions involving ultraviolet radiation from the Sun.
- Chemical reaction- Reactive halogen gases cause chemical depletion of stratospheric ozone over the globe.
- Removal- Air containing reactive halogen gases returns to the troposphere where the gases are removed by moisture in clouds and rain..
Reports from NASA and NOAA in late 2014 showed that the Antarctic Ozone Hole holds steady, providing some hope that this is a sign of recovery for Earth's protective ozone layer.
But now it is feared that this all cautious effort taken to protect the ozone layer will be spoiled by the intervention Climate change.