Fact sheet page: 1 2 3 4 5 6 7 8 9 Quiz 1999 Quiz 2000
Production of the industrial chemicals which once posed a major threat to the ozone layer has been greatly reduced, and levels of some of these chemicals are now beginning to decline in the lower atmosphere.
The ozone layer is expected to eventually recover, if all nations maintain their efforts to reduce ozone-destroying chemicals. However, it will probably be more than a decade before we begin to see definite signs of a recovery, and at least the year 2050 before any substantial recovery occurs. At present, the layer is still thinning, especially at the earth's poles. The "hole" over the Antarctic continues to remain large and considerable depletions are occurring in the Arctic.
Mid-latitude areas, such as southern Canada and the U.S., are also still experiencing ozone thinning.
Canada has played a key role in protecting the ozone layer. Our nation was instrumental in the development of the Montreal Protocol, the international agreement to reduce ozone-destroying chemicals. Canada is also a leader in the scientific research which guides international action to protect our fragile skies. Canada's Meteorological Service provides the most accurate ground-based ozone measurement instrument in the world, the Brewer Ozone Spectrophotometer and uses the WMO Global Ozone Observing System and World Ozone and Ultraviolet radiation Data Centre.
Canada [MSC] provides the most accurate-based ozone measurement instrument inthe world network and maintains the WMO Global Ozone Observing System primary calibration reference and World Ozone and Ultraviolet radiation Data Centre.
Yet, we still have much to do - we must find ways to reduce the use of the remaining industrial chemicals that continue to damage the ozone layer, and to guard against any new threats. Scientists need to learn more about ozone depletion, and how other stresses on the environment, such as climate change, are affecting the upper atmosphere.
Fact sheet page: 1 2 3 4 5 6 7 8 9 Quiz 1999 Quiz 2000
This fact sheet is part of a series on air issues.
Other fact sheets in this series include:
Smog, Acid Rain, Air Toxics (Fall 1999)
Cette publication est aussi disponible en français.
Minister of Public Works and Government Services Canada, 1999.
The Green LaneTM,
Environment Canada's World Wide Web Site.