Molina and Rowland, CFCs, and protection of the ozone layer

The ozone layer protects us from something harmful. The opening establishes that ultraviolet light contributes to skin cancer, then explains that ozone screens out much of the sun’s most damaging ultraviolet radiation. That gives us a reason to care about what happens next: damaging this protective layer lets more harmful radiation through.

Molina and Rowland identified a threat to that protection and pushed governments to respond. Keep both parts of their work in mind. This is a story about scientific research leading to public action, not just a description of a chemical reaction.

First, we need to understand what humans are changing. Ozone is naturally produced and destroyed. Those processes ordinarily stay in “rough equilibrium,” so natural destruction does not by itself mean that the layer keeps shrinking. The problem is adding something that disrupts that balance.

That something is CFCs, manufactured chemicals used in products such as sprays and refrigerators. After their release near the ground, the gases slowly move into the stratosphere. There, ultraviolet radiation breaks them apart and releases chlorine. The chlorine reacts with ozone, destroying the ozone while regenerating the chlorine. So the chlorine can keep doing damage instead of being used up in a single reaction. One chlorine atom could destroy as many as 100,000 ozone molecules before becoming inactive. That explains why this is such a serious threat.

Stopping production would help, but it would not make the existing CFCs disappear. In 1974, the atmosphere already held an accumulation equal to five years of global production. Those chemicals would continue moving upward and breaking down. The scientists therefore predicted that ozone depletion would continue for years, perhaps decades, even if production and use stopped immediately. The five-year figure measures the accumulated amount; it is not a five-year deadline after which the damage would end.

That delay makes action urgent. Waiting for more damage means allowing still more CFCs to build up. Molina and Rowland took their findings to policymakers, and Molina testified before Congress. They were trying to get a policy response proportionate to the threat they had identified.

They met resistance, especially from scientists tied to the CFC industry. But later evidence supported their views, including the discovery of the Antarctic ozone hole. The account ends with concrete changes: the 1987 Montreal Protocol aimed to ban production of ozone-depleting gases, while North America had already banned CFCs in the late 1970s. Product packaging changed, and more environmentally friendly refrigerants were developed.

That ending answers the question the research raises: did anyone act on this? Yes. The scientists helped expose the threat and bring about changes in policy and products. The author’s point is the successful connection between research, advocacy, and action.