Environmentalists can be a depressing lot. Nothing seems to be good in their world. Too many people, no clean water, global warming, rising seas and toxins everywhere. I am guilty of spreading these messages on a regular basis.
But, it is worth noting some success stories during the past half-century, when people got concerned about human impacts on the planet. One of the first was built off Rachel Carson’s book, Silent Spring, which is still criticized by many, but led to banishing DDT as an insecticide in North America. DDT had been linked, albeit indirectly, to eggshell thinning on large, predatory birds that got a big dose of it from their position at the top of the food chain.
Result? Without DDT, Ospreys, Bald Eagles and pelicans have returned in good numbers to the lower 48 states, where they were nearly absent 40 years ago. The DDT story leaves a legacy of concern about endocrine disruptor chemicals that are released to the environment. We see their effects on nature, but seem less concerned about what they might do to us.
Another success is the removal of lead from gasoline. Companies that mine and process lead were dead-set against that legislation, saying there was no good alternative to prevent engine “knock.” But, bright chemical engineers found that cars could run just fine on lead-free gas, with alternative additives. Along with the removal of lead from paints, the elimination of lead from gasoline is linked to lower levels of lead in blood samples of urban children, where lead poisoning is linked to poor mental development. Recent layers of snow in the Greenland ice pack carry lower levels of lead, showing that we have cleaned up the atmosphere with respect to lead pollution.
Chlorofluorocarbons (CFCs) must also be on the list of success stories. In 1974 when Sherwood Rowland and Mario Molina first elucidated the chemistry that showed how CFCs might destroy stratospheric ozone, no one paid much attention to them. The manufacturers of CFCs geared up to defend their product. But by the early 1980s, it was clear that the ozone layer was thinning over Antarctica—just where Rowland and Molina said it would—and CFCs were the likely culprit. Even recently, I’ve met folks who don’t believe the linkage, but the international ban on CFCs and the subsequent and ongoing recovery of the ozone layer are proof enough for me.
These success stories show that when we get serious about a problem, even if the science is not fully closed on the issue, we can do something positive for the environment, with good effect. And, we need to make sure the alternatives don’t introduce problems of their own. Methyl tert-butyl ether (MTBE) was added to gasoline as an anti-knocking agent until it too was shown to cause undesirable environmental problems.
The story is not all bad, and seeing Bald Eagles along the coast of Maine this summer makes me think of the good things that have come from environmental science.
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Champoux, L., J.-F. Rail, R.A. Lavoie, and K.A. Hobson. 2015. Temporal trends of mercury, organochlorines and PCBs in northern gannet (Morus bassanus) eggs from Bonaventure Island, Gulf of St. Lawrence, 1969-2009. Environmental Pollution 197: 13-20.
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 For those who enjoy fine wines, it is interesting to note that the content of organolead compounds in Chateauneuf-du-Pape peaks in 1962 and declines rapidly in the years following as triethyllead was banned from gasoline.
 A few years ago, I corresponded with one fellow who said that until I could document a penguin blinded by cataracts from excessive ultraviolet light in Antarctica, he would not believe the ozone hole was real or unnatural. When I pointed out that such a blind penguin would be easy prey for leopard seals, our email exchange ended abruptly. Still, I am sure he was not satisfied. Often people believe only what they want to believe.