It was 45 years ago, on September 25th, 1974, that scientists alerted the world to the environmental damage being caused by chlorofluorocarbons (CFCs). The 'miracle compound,' freon, representing several different CFCs, had been invented in 1928 for use in refrigeration and spray cans. It was regarded as safe because it was non-toxic, non-inflammable, and largely non-reactive, unlike dangerous alternatives such as ammonia.
The study revealed, however, that CFCs made their way to the upper atmosphere, where ultraviolet radiation broke them down and released their chlorine to attack the ozone layer. The Earth's high ozone later shields the surface from much of the ultraviolet radiation that might otherwise increase cases of skin cancer in humans and genetic damage to many organisms. Research showed this breakdown was indeed happening, with a hole in the ozone layer over Antarctica that was increasing in size.
The international community sprang into action in what is regarded as a successful response to an environmental threat. The Montreal Protocol in 1987 banned the production of CFCs, halons and other ozone-depleting chemicals, and took effect from 1989. Industry responded by developing ozone-friendly alternatives to CFCs, starting with hydrochlorofluorocarbons (HCFCs), one of which is now used in motor car air conditioners. Hydrocarbon refrigerants began to supersede CFCs in domestic and commercial refrigeration. The manufacture of new CFCs virtually ceased in 1994, though some are still used in aircraft halon fire suppression systems until a safe and effective substitute can be developed, and very small quantities are still permitted for some "essential" uses such as asthma inhalers.
The ban began to achieve the desired result. Ozone levels in the upper atmosphere had stabilized by the mid-1990s, and began to recover by the early years of the current century. The ozone hole was observed to be shrinking, and recovery is expected to continue over the course of the century.
What made the action effective is that it used technology rather than trying to impose behavior changes. People still used air conditioners, but now with safe alternatives to the freon they had previously used. People still used spray cans, but now many of them used hand pump action in place of gas pressure, and the ones that still used pressure relied on different and more environmentally-friendly gases. Industry and people readily turned to the new alternatives because they required no lifestyle changes.
This is something many environmental campaigners today fail to appreciate. Calls for us all to "live more simply" are likely to fall on deaf ears, whereas calls for new and more environmentally-friendly technologies to be adopted are more likely to succeed. The move to replace fossil fuel vehicles with electric ones is gathering pace, as is the switch from producing electricity from coal and oil to generating it from the much cleaner gas, or from cleaner still solar and wind produced energy. People are unlikely to stop driving or flying in response to hysterical cries of impending doom, but they are likely to drive and fly by very much more planet-friendly methods. As with the reduction in CFCs, nations are already responding with alternative technologies that cut the carbon footprint.
The lesson of the drive to replace freon with non-damaging alternatives is that technological innovation succeeded where exhortations to change behaviour would almost certainly have failed. The solution is not to live more simply; it is to live more cleverly.