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Ozone Day:
September 16th, 2021

The United Nations International Day for the Preservation of the Ozone Layer is celebrated each year around the world on September 16, a date that marks the 1987 signing of the Montreal Protocol. 

This international treaty was enacted to protect the ozone layer by eliminating the use of ozone-depleting substances and has led to the phase-out of 99 per cent of ozone-depleting chemicals in refrigerators, air-conditioners and many other products. These efforts have provided protection for the ozone layer and in doing so, helped to improve human and ecosystem health by limiting incoming harmful UV radiation. The phasing out of HFC’s and CFC’s has also contributed significantly to combating climate change by reducing the atmospheric concentration of these known contributors to global warming. 

This year’s theme, “Keeping Us, our Food and Vaccines Cool” focuses attention on the need to understand the impact of ozone in each of these key areas.

To help celebrate this important occasion, primary and secondary school educators throughout the world are encouraged to organize classroom activities that focus on topics related to ozone, the ozone layer and the connection between ozone action and climate change.

Why Care About The Ozone Layer?

  • The ozone layer acts as an atmospheric shield.  All life on earth depends on its protection from the lethal levels of ultraviolet radiation produced by the sun.
  • Cause and effect has been established between a thinning of the ozone layer and increased incidence of skin cancer.
  • Declines in crop yields of up to 50% in some countries have been linked to increased amounts of incoming UV radiation.  A thinner ozone layer is also a factor in the declining concentrations of phytoplankton that support aquatic food webs.
  • Products emitting ozone depleting substances are still produced and consumed throughout the world.
  • Many ozone depleting substances remain active in the atmosphere for 50 to 100 years.
  • Most ozone depleting substances are also greenhouse gases.
  • Protection efforts to date are making a difference.  Parts of the ozone layer have recovered at a rate of 1-3% per decade since 2000. At projected rates, Northern Hemisphere and mid-latitude ozone will heal completely by the 2030s.  Complete global healing is expected by 2060.
  • Ozone layer protection efforts have also contributed to the fight against climate change by averting an estimated 135 billion tonnes of carbon dioxide equivalent emissions, from 1990 to 2010
For more information and activities be sure to check out the International Day for the preservation of the Ozone Layer website.