Ozone Depletion

Click on any of the following to learn more:
 

What exactly is the Ozone?
The Ozone hole is an area of the ozone layer that is seasonally depleted of ozone. The Antarctic ozone hole now appears in the region of the South Pole every September, and it is replenished in November and December. In recent years, this hole has covered an area of about ten million square miles.
Spring in the Antarctic brings a light that harms instead of nurtures. In this season of new beginnings, the hole in the ozone layer reforms, allowing lethal ultraviolet radiation to stream through Earth's atmosphere.
The hole lasts for only two months, but its timing could not be worse. Just as sunlight awakens activity in dormant plants and animals, it also delivers a dose of harmful ultraviolet radiation. After eight weeks, the hole leaves Antarctica, only to pass over more populated areas, including New Zealand and Australia. This biologically damaging, high-energy radiation can cause skin cancer, injure eyes, harm the immune system, and upset the fragile balance of an entire ecosystem.
Although, two decades ago, most scientists would have scoffed at the notion that industrial chemicals could destroy ozone high up in the atmosphere, researchers now know that chlorine creates the hole by devouring ozone molecules. Years of study on the ground, in aircraft, and from satellites has conclusively identified the source of the chlorine: human-made chemicals called chlorofluorocarbons (CFCs) that have been used in spray cans, foam packaging, and refrigeration materials.

Could the Ozone Layer be Declining?
Monitoring ozone levels in the south polar region, researchers found them to be consistently about 35 percent higher in late spring than in winter. Annual monitoring showed the same seasonal pattern through the late 1970s.
All of a sudden, in 1978 and 1979, the British scientists found something different. In October, the beginning of spring in the southern hemisphere, the researchers detected less ozone than had been detected during the past 20 years. During the next several years, October ozone levels continued to decline. (See graph below of researchers evidence)

Working Together to Make it Better
Dramatic research on ozone and the atmosphere over the past 40 years has led to a global ban on CFC production. Since 1987, more than 150 countries have signed an international agreement, the Montreal Protocol, which called for a phased reduction in the release of CFCs. Later, modifications of the treaty called for a complete ban on CFCs. Even with this ban in effect, chlorine from CFCs will continue to accumulate in the atmosphere for another decade. It may take until the middle of the next century for ozone levels in the Antarctic to return to normal levels.
More globally, ozone depletion is expected to remain a fact of life for several decades to come, but thanks to the research that led to early recognition of the problem and steps that have been taken to address it, the potential consequences are much less severe than they otherwise would have been.
 
 
 
 

Satellite image of the ozone hole (pink area) over Antartica taken on September 25, 1995.
 
 

Ozone loss over the South Pole in 1995 (in green) compared with 1993 (in red). The blue line shows values
before ozone destruction began. The  high technology used to design this graph would later be used to detect the two primary sources of the ozone-devouring chlorine atoms over Antarctica; which were the CFCs and two other pollutants, the industrial solvents carbon tetrachloride and methylchloroform.
 
 

To learn more about CFC's,click on one of the following:
                                   www.ciesin.org
                               www.cmdl.noaa.gov

To learn more about Laws pertaining to ozone depletion, click on one of the following:
                                                            http://www.unmfs.org/
                                                           http://www.unep.org/ozone/

To learn more about Research performed in regards to the ozone, click on onf of the following:
                                                  http://www.cmdl.noaa.gov/spo/
                                      http://www.physics.iastate.edu/atmos/index.html

To learn more about harmful effects of the ozone hole, click on one of the following:
                                          http://www.atm.ch.cam.ac.uk/tour/index.html
                                                             http://irg.usask.ca/

For an overall view of the ozone depletion phenomenon, click on the following:
                    http://www.beyonddiscovery.org/content/view.article.asp?a=73