Refrigerants for the 21st Century
9. Proof of CFC Damage

Because of the complexity of the atmosphere, scientists resorted to computer modeling to try to include as many variables as possible. Even so, the best that could be hoped for was a two dimensional model.

Initial attempts at stratospheric measurements of key chemical species were very crude. However, laboratory experiments about equilibria and kinetics showed which molecules and free radical species should be most important to O3 chemistry.

While the scientists scurried to develop an understanding of the problem, politicians, civic leaders and manufacturers of CFC's had to take positions. There were calls for boycotts of CFC-containing products. Some companies voluntarily chose to eliminate CFC's from their products. A representative of Dupont, the world's largest producer of CFC's, at the the Philadelphia ACS meeting, stated that their production must cease IF the theory could be shown to be correct. In 1979 the U.S. government and those of some Scandanavian countries chose to ban the use of CFC's in aerosol products (except for a few critical medical applications, such as anti-asthma inhalers). At the time aerosols were the largest (28%) single use of CFC's.

With the U.S. government ban on CFC-using aerosol products, there was a temporary leveling off of in CFC's production. The ban would have had a more dramatic effect if most of the other nations of the world had followed suite. After all, the problem of atmospheric pollution is worldwide. By 1985, the CFC's production rate was again growing - at a 3%/year rate. Countries from around the world met for the first time, in Geneva, Switzerland in 1985, and signed a convention calling for negotiators to make plans for a worldwide course of action based on the latest scientific information. Not only CFC's but Br-containing halons as well were to be included in computer-generated models.

The first concrete evidence for stratospheric O3 damage came in 1985 when British scientists reported finding dramatic declines in the springtime O3 values above the Antarctic. The "hole" was first detected in the mid-1970's through analytical samples taken in the stratosphere using instruments attached to huge balloons.