In the 1970s, the Earth’s ozone layer came under attack. More than 30 years later, the ozone layer's future is looking a lot brighter!

What depleted the ozone in the first place?

Gases containing chlorine and bromine (called ozone depleting substances, or ODS) resulted in the destruction of ozone in the stratosphere, reducing our atmosphere’s ability to block harmful solar radiation from reaching the Earth’s surface.

Did you know? It can take up to a century to clear ODS’s from the atmosphere.

Ozone forms naturally by a reaction of oxygen with sunlight, so ozone depletion can be understood as a lack of balance between processes of ozone creation and destruction. While ozone depletion has had a worldwide effect, warming of ODS-rich winter air over Antarctica produced a severely depleted “ozone hole” in that specific location.

Did you know? In 2006 the Antarctica “ozone hole” reached the record size of 10.6 million square miles (larger than North America).

How is the ozone today?

In 1987, the Montreal Protocol was adopted to limit production of ozone depleting substances. It was a landmark decision on an environmental issue and more than 196 countries signed on. Former United Nations Secretary General Kofi Annan calls the agreement “perhaps the single most successful international agreement to date.”

Today, we can thank the Montreal Protocol for putting the brakes on ozone depletion. Since ozone can regenerate itself naturally in the absence of ODS’s, research is now showing that the Antarctic ozone hole is on the mend. In fact, according to the 2010 Scientific Assessment of Ozone Depletion, the Antarctica ozone hole is projected to return to 1980 levels around 2040, although this is later than any other region.

The Montreal Protocol tells us that governments, industry and science can work together to address environmental issues — for the health of our complex, evolving world, we must make sure that the necessary cooperation happens.

What can I do?

The Montreal Protocol successfully reversed ozone depletion, but emissions of nitrous oxide, methane, and carbon dioxide pose a remaining, unregulated threat to the ozone layer. Here are a few ways you can make a difference:

  • Learn about the industries in your city and their impact on the atmosphere and environment, then write to your federal and provincial government representatives with any concerns you may have
  • Encourage your politicians to support another international environmental effort, the Kyoto Protocol, which aims to minimize global warming and climate change
  • Embody an environmental ethic — reduce, reuse, recycle and choose products whose manufacturer has minimal environmental impacts
  • Think about a career where you could make a difference — work as a scientist, green-engineer, policy-maker, educator, or environmental advocate
  • Share this story, the Montreal Protocol worked and, in this age of cynicism, that is an immensely inspiring message!
  • Learn More!

    NASA’s Ozone Hole Watch


    THE SCIENTIFIC ASSESSMENT OF OZONE 2010 World Health Organization/United Nations Environmental Programme


    Article first published in 2011.

Sandy Marie Bonny

I am a geobiologist with a doctorate in Earth and Atmospheric Sciences from the University of Alberta. I work as a sessional lecturer, science writer, and creative writer - and yes, the science is almost always stranger than my fiction!

Comments are closed.