In an age when involuted political scandals and celebrity lawsuits often stand as the principal issues of the day, it is amazing to consider that a mere three decades ago, American public discourse was seized by a slow-reading technical volume from a former staff biologist of the sleepy Fish and Wildlife Service. As galleys of ““Silent Spring’’ circulated, chemical companies threatened lawsuits to block publication. Once in stores, the book was an overnight best seller, extremely rare for a serious work. Carson’s words were denounced in some quarters (including by Newsweek) as hysteria, lauded in others as a breakthrough. President John Kennedy appointed a commission to study the conclusions of ““Silent Spring,’’ and Carson became an international luminary, her book hailed as one of the century’s most important.
What did ““Silent Spring’’ foresee? ““The robin seems to be on the verge of extinction,’’ Carson wrote in an eye-catching paragraph. Robins were among the most prolific birds in North America: the notion that they might soon join the dodo on nature’s backlist helped make ““Silent Spring’’ a sensation. Carson thought that indiscriminate pesticide use was killing off many bird species directly and triggering genetic resistance among insects that attack crops. Soon pesticides might also render extinct a key ““friendly’’ species, the earthworm, breaking the food chain of many avians. No birds would be left to greet the next winter’s end with song. There would come a silent spring.
It is the fate of the birds, at the heart of her analysis, that conveys the most dramatic difference between what Carson foresaw and what later occurred after her warnings were heard. The robin easily evaded extinction; today its red breast remains ubiquitous at backyard feeders. Another bird Carson thought about to vanish, the bald eagle, has (since the banning of DDT) bounced back so spectacularly that it is in the process of being ““delisted’’ from endangered-species status. At Newsweek’s request, Bruce Peterjohn, chief analyst for the North American Breeding Bird Survey, compiled annual population trends for 40 birds and their subspecies depicted as near extinction in Carson’s chapter ““And No Birds Sing.’’ Of those 40 birds, 19 have had stable populations since 1966 (the first year for which comprehensive bird data is available), 14 have shown population increases and seven have fallen. This sounds like business as usual for nature, since most ecologists now believe relative species populations would vary whether there were human meddling or not.
None of Carson’s other major predictions has come to pass. For instance, ““Silent Spring’’ projects that cancer caused by synthetic chemicals could become endemic, so much so that even humanity might fall extinct. (Carson knew she had breast cancer when she wrote ““Silent Spring,’’ and it claimed her life in 1964.) After the birds and the people were gone, Carson supposed, mutated insects would inherit the earth, made stronger by the very poisons chemists designed to destroy them. When ““Silent Spring’’ was published, pesticide use was reckless; synthetic chemicals were believed to account for up to 90 percent of cancers; few federal programs existed to combat industrial excess. There was reason to be terrified by what Carson called her ““fable for tomorrow,’’ in which ““a town in the heart of America’’ ends up lifeless, every human and animal poisoned.
Yet even taking AIDS into consideration, overall U.S. public health has steadily improved. Lung cancer caused by cigarette smoking has reached dreadful proportions, but most other cancers are either declining or, at worst, up slightly, when the aging of the population is taken into account. Richard Doll, the British researcher who first proved the link between cigarettes and lung cancer, now estimates that synthetic chemicals cause less than 5 percent of human cancers.
Next, though agricultural chemicals are still overused, neither pesticide toxicity nor insect mutations has progressed to the runaway level. Highly potent agricultural chemicals such as chlordane, dieldrin and DDT – Carson’s leading concern – have been banned. The tonnage of synthetic compounds used in agriculture has gone up since Carson’s day, but most farm chemicals have been reformulated to render them biodegradable. Most have narrow toxicity (killing only a specific insect or weed) versus the broad toxicity (capable of killing mammals as well as bugs and plants) of the 1950s substances Carson studied.
Further, Carson feared that as insects mutated into superbugs, general aerial spraying of insecticides would become an everyday event, as, in 1959, parts of Detroit were dusted from low-flying planes with aldrin, a broad toxic since banned, in an attempt to control the Japanese beetle. Such unannounced urban bombardment would have been crazy even if the substance in use was champagne, to say nothing of a powerful poison. Yet contrary to Carson’s expectation, wide-area spraying of insecticides has become so rare that the two times this has happened in the past decade, during California’s medfly episodes, it has been headline news.
Of course such turns of events hardly ensure that new environmental threats are not in the making. For instance, recent studies suggest that several types of neotropical migratory birds, a category not emphasized by Carson, are in decline. But most trends suggest silence in spring is unlikely to come.
Surely this is because Carson’s warnings helped inspire a revolution in environmental protection. Since ““Silent Spring,’’ the EPA has been established; the Endangered Species Act has been passed; sweeping air-and water-pollution control laws have gone into effect; forest preservation has become a prominent cause; chemical safety has become a leading concern; conservation generally has become a core American political value. For any prominent thinker’s warning of disaster to be wrong is the best possible outcome for society, if reform explains the discrepancy between forecast and result. That the predictions in Rachel Carson’s masterpiece did not come true should be seen as the greatest aspect of her legacy.
