Introduction
Antarctica

During the 1970's, a reduction in the amount of stratospheric ozone over Antarctica was discovered by scientist with the British Antarctic Survey. The BAS, which had been tracking the amount of stratospheric ozone over their outpost on Antarctica since 1957, found that measured levels began to fall of steeply from their baseline figure of about 300 Dobson Units (DU). By 1985, the levels had fallen to about 200 DU, and reports began to circulate in the popular press about the "Ozone Hole" that had developed over the Antarctica. Of course, some scientists had predicted that this type of event would be happening. In 1974, Drs. Mario Molina and F. Sherwood Rowland predicted that chlorine from chlorofluorocarbons (CFC's) would destroy ozone in the stratosphere. For their work, they were presented the Nobel Prize in Chemistry in 1995.

The reporting of the thinning of the ozone layer over the Antarctica thrust a new issue concerning global climate change at a public that was still reeling from the discussion of industrial pollutants in the 1970's. People who had never even heard of the words stratospheric or ozone were suddenly being presented with evidence that mankind had literally put a hole in the sky that was going to allow harmful radiation in. Reaction to this was swift, and lobbying efforts began to get the government to correct the problem. In 1987, the Montreal Protocols were signed by 155 nations that would phase out the use of CFC's over the succeeding decades. With the phase out of CFC's, the levels of free chlorine in the stratosphere should drop, and the ozone layer should thicken as natural processes that create ozone replenish the layer.

Angst, Apathy, and Business

For most people, the repairing of the ozone hole is a critical issue. However, this opinion is not universal. The elimination of CFC's has required some industries to re-think their standard equipment and practices. The air conditioning industry has been especially affected by this phase out. Most cooling systems used freon 12 (a CFC) as a refrigerant. The proposed phase out has caused this industry to search for new refrigerants, which has resulted in a need for a change in equipment to use these. For the installation of new equipment, this has not presented too much of a problem, as the difference in cost is negligible between the old and new equipment. However, for the repair of old equipment, it has created tremendous costs, which have been passed down to the consumers. One of the growing markets in the smuggling industry is for freon 12 from Third World countries that are still allowed to make it for people to use in repairing old refrigerators and air conditioners.

This hit in the pocket book has caused some people to question the Montreal Protocols. For some, the issue is somebody else's problem. Since the "Ozone Hole" is over the Antarctic, they do not feel the need to inconvenience themselves for a place where nobody lives. This view, of course, is incorrect, since the measured levels of stratospheric ozone are less all over the world; it is only over the South Pole that the layer is thin enough at certain times of the year to qualify as a hole. In the Northern Hemisphere, stratospheric ozone levels have dropped somewhere between 10%-40% during winters over the last several decades. For other people, it is a question of biased science. There claim is that none of the science behind ozone depletion is "proven", and that changes that hurt the economy should not be taken until it is. As Congressman Tom DeLay (Republican, Texas) said after the Nobel Prize had been awarded in 1995, "I am puzzled at how the Swedish Academy of Sciences could award to these professors the Nobel Prize in Chemistry for theories that have yet to be proven." DeLay, a former exterminator, further stated, "I do not want to question the motives of the Swedish Academy, but I must note that Sweden is dominated by the agenda of radical environmentalists who not only want to ban CFCs but also all substitutes for CFCs."¹

The websites below present information about stratospheric ozone and the controversy surrounding it.

Ozone Hole Information

EPA
University of Cambridge

Pro CFC Ban

United Nations
Friends of the Earth

Anti CFC Ban

CFACT
The Science & Environmental Policy Project

After reading through these and any other sites that you might find, answer the following questions

• What are some of the expected consequences of a thinning stratospheric ozone layer?
• Is the connection between ozone depletion and CFC's strong enough to warrant government regulation of CFC's?
• How is global warming tied to the thinning of the ozone layer? Are they the same issue?