PLAINFIELD, N.H. — The unfolding story of saving the ozone layer is beginning to be good enough to make one believe in the rationality, flexibility, maybe even long-term viability of the human race. In London in late June, representatives from 93 nations took a second important step to protect the ozone that protects us all.
The first was the Montreal Protocol in 1987, when 56 nations agreed to cut production and use of the five most widely used chlorofluorocarbons (CFCs) by 50% by the year 2000. Never before, people said, had the nations of the world cooperated to prevent an environmental catastrophe from happening.
The danger of CFCs is well understood--they escape into the atmosphere and destroy ozone, thereby allowing damaging ultraviolet light to reach the Earth's surface. Molecule for molecule, CFCs also produce a greenhouse effect thousands of times greater than that of carbon dioxide. Once in the atmosphere, they can stay there for a century.
But there were snags in and doubts about the Montreal Protocol. Few Third World countries signed it. China pressed on with its campaign to provide all its people with refrigerators (200 million of them), which use CFCs as coolants. India's CFC use increased at the phenomenal rate of 30% per year. Even if the two countries had signed, a 50% worldwide cut by 2000 would allow CFCs to keep increasing in the atmosphere for more than 100 years, reaching twice their current level. It was likely that the Montreal Protocol didn't go far enough.
The agreement included the stipulation, though, that the world's nations must convene regularly, review the evidence and strengthen the provisions, if necessary. Hence the London meeting a week after new measurements showed that ozone is being depleted more rapidly than had been thought.
Since 1967, the ozone layer over the equator has decreased by 3%, over Europe and North America by 10%. Each 1% decrease can lead to a 3% to 6% increase in skin cancer.
So the London meeting committed protocol signers to phase out the original five CFCs not by 50%--but completely by the year 2000. It added other ozone-destroying chemicals to the list: methyl chloroform, carbon tetrachloride and halons. And to entice Third World nations to join, it set up an international fund--$240 million so far--to help them afford the transition to a CFC-free world.
There are four strategies to cut our CFC dependency:
--Stop trivial uses. Life will still be liveable if fast-food hamburgers are sold in cardboard instead of plastic foam. We can probably get along without polystyrene packaging for peanuts and spray-on shoe polish. Most of us can exist without an air conditioner in the car. Because drivers want their car cooled in a hurry, the air conditioner contains 10 times as much CFC as a refrigerator. It also leaks. It would be better for the ozone layer just to roll down the windows.
--Capture and recycle. The halons, which extinguish fires without toxicity and without leaving any residue, released in testing fire extinguishers could be reused. (Only 7% of halons released come from actual fire-fighting.) Some electronics companies are already recycling CFC solvents. The CFCs vented when coolers and air conditioners are serviced can be caught and used again.
--Non-CFC substitutes. Circuit boards can be cleaned with acidic or alkaline water solutions. Refrigerators can use other gases--helium--as coolants. Many materials besides polyurethane foam can insulate houses. Non-halon-containing fire extinguishers already exist. The United States banned CFCs as aerosol propellants in 1978 and no one noticed, because other gases (carbon dioxide, pentane, nitrous oxide) took their place.
--CFC substitutes. Some CFCs are worse ozone eaters than others. The chemical HCFC-22, widely used in home air conditioners, causes only 5% as much ozone destruction, molecule for molecule, as CFC-12, which is used in car air conditioners. Because HCFC-22 is not regulated by the Montreal or London protocols, there's a strong drive to substitute it for many CFC uses. When McDonald's tells you that their foam hamburger cartons no longer hurt the ozone layer, what they mean is that they now use HCFC-22, which doesn't hurt the ozone layer as much.
Some of these changes will save money--especially recycling and doing away with trivial uses. Some will cost more--especially the CFC substitutes. Most will create headaches for industry. Equipment will have to be redesigned, workers retrained, chemical plants refitted. Du Pont, which currently makes 25% of the world's CFCs, is investing in four new plants to produce CFC substitutes.
That most of the world's nations are willing to go to all this trouble, and even to help each other do it, does not mean the human race has suddenly become angelic. There was plenty of politics-as-usual leading up to the London meeting. Maybe the best news in the ozone story is that sensible results can be achieved even through politics-as-usual.