Chapter 29 From the Past to the Future: 1968-2000
Section 3 Environmental Challenges
The wars that broke out in the aftermath of the Cold War were not the only threats to the well being of the peoples of the planet. As the earth’s population continued to grow, technological developments and industrialization led to greater and greater manmade changes in the environment. Scientists and environmentalists warned of the potentially harmful effects of continued pollution and loss of biodiversity.
Civilization and Pollution
As the world population continued to grow after World War II, and industrialization and urbanization continued to spread, people became more aware of the impact such growth had on their environment. As cities spread into surrounding areas, and as factories sprang up in what had been farmland, both spread pollution across entire regions. Perhaps the worst cases of pollution by the 1990s were to be found in the former Soviet Union, where decades of unregulated industrial pollution had left a catastrophic legacy. Similar problems confronted peoples around the world, however.
Acid Rain. The growing problem of pollution also demonstrated the increasingly regional and international effects of industrial growth. Apart from fallout from nuclear accidents like that at Chernobyl, perhaps the most devastating new pollution was acid rain—a vinegar-like mixture produced when atmospheric moisture, such as rain or snow, falls through air filled with such common products of combustion as sulfur dioxide and nitrogen oxide. During the decades after World War II, acid rain ravaged the fabled Black Forest of southern Germany, as well as other forests in Scandinavia. It also wiped out fish populations in lakes across Scandinavia, the northeastern United States, and Canada, and damaged ancient buildings such as the Parthenon in Greece.
Ozone Depletion. Some scientists also attributed the apparent depletion of the ozone layer of the stratosphere to the effects of industrialization. A form of oxygen with three atoms rather than the usual two, ozone serves the beneficial purpose of blocking ultraviolet radiation from the sun. Most plant and animal species, as well as humanity, have developed mechanisms to deal with historically normal amounts of ultraviolet radiation. Unusually high levels, however, can be damaging—causing skin cancers among humans, for example, as well as the destruction of many plant and animal species.
During the 1980s and 1990s, atmospheric scientists noticed that a large hole developed seasonally in the ozone layer over Antarctica. Many feared that the phenomenon would spread to other parts of the globe. Although the full mechanism ozone depletion was still unclear, some believed that a major culprit was chlorofluorocarbons (CFCs)—carbon-based combinations of chlorine and fluorine that had been used for years in such things as aerosol spray cans, refrigerants, and the manufacture of plastics and electronic components. Some scientists believed that CFCs released into the atmosphere drifted upward to the stratosphere, where they broke down the ozone. Though not all scientists agreed with this analysis, during the 1980s and 1990s the major industrial countries cut back on the use of CFCs. In 1994 Germany banned CFC production, while the U.S. and Canada decided to phase out CFCs by 1996.
The problem of pesticides. Not all pollution was a matter of industrial waste. As the world faced a growing population in the 1950s scientific researchers began to produce a vast array of new chemicals, including fertilizers and pesticides, to help increase food production and to eradicate disease-carrying insects. Perhaps the most popular of the new chemicals was the “miracle” pesticide DDT. Use of the new products not only led to greater food production but also to declining death rates.
Not everyone was so certain of the long-term beneficial effects of these man-made products, however. One of the most influential opponents of the new chemicals was the American biologist Rachel Carson.
BIO Born in 1907 in Springdale, Pennsylvania, Carson had been raised in what was still a predominantly rural America. Encouraged by her parents, she attended university and eventually became a biologist. After teaching at the University of Maryland from 1931 to 1936, Carson joined the U.S. Bureau of Fisheries, where she remained until 1952.
An ardent conservationist, Carson soon began to worry about the effects of man-made chemicals on the natural environment. After publishing several books on the sea, in the late 1950s and early 1960s she turned her attention to the new “miracle” chemicals. After careful study, in 1962 she published a highly controversial work, Silent Spring, warning that overuse of the new pesticides, especially DDT, was killing wildlife and polluting the entire environment.
“These insecticides are not selective poisons. They do not single out the one species of which we desire to be rid. Each of them is used for the simple reason that it is a deadly poison. It therefore poisons all life with which it comes in contact.”
Using the case of a small Michigan town, Carson documented how the use of DDT to kill beetles, which were destroying the town’s elm trees, had unexpected effects. In addition to killing the beetles the DDT was also absorbed by the trees. As the leaves fell, they were eaten by worms, which in turn were eaten by the town’s robins. Soon, nearly all the robins had died. “What has silenced all the voices of spring in countless towns in America?” Carson had asked. The answer was clearly DDT. Particularly disturbing was the idea that the poisonous DDT might easily get into the human food chain.
Carson died in 1964 without seeing her warning acted on. Her
efforts, however, inspired major investigations and eventually, in 1972,
the U.S. Environmental Protection Agency banned the use of DDT—though it
continued to be used heavily overseas, especially in the Third World. In
the meantime, Silent Spring had provided the stimulus for a new movement of
environmental activism that soon spread from the United States to Europe
and other parts of the world.
Global warming. As the 1900s drew to a close, some scientists also began to worry about global warming. The burning of fuels, such as gasoline or coal, released carbon dioxide into the atmosphere. This carbon dioxide, they warned, trapped heat near the earth, a process called the greenhouse effect. Since the Industrial Revolution, they argued, human beings had increased the output of carbon dioxide so much that it threatened to raise global temperatures. Not everyone agreed, however.
More cautious scientists noted that data on global warming trends
was very limited—records did not go back before the 1800s. In addition,
geologists and geographers pointed out that the earth had experienced many
periods of warming and cooling over its lifetime—there was little way to
know whether the current trend was caused by industrialization or not. As
the controversy continued, one well-known and respected geographer warned:
“The true legacy of
[the] global warming [notion], which the data argue is much more benign
than it is perceived to be, will be the destruction of the public’s
faith in science. Tragically, it will be noted by historians in the 21st
century, that even by the mid-1980s, the data had indicated that the
then-popular vision of climate catastrophe was a failure.”
Global warming remained a controversial issue until the first decade of the 21st Century. By 2006, however, the growing body of data, including the melting of glaciers and the polar icepacks, left few scientists in doubt about the dangers and more and more governments around the world began to listen to the warnings. By 2007, even the previously skeptical U.S. Administration of President George W. Bush had accepted the reality of global warming.
In addition to other problems, the growth of population in many countries also led to the destruction of large amounts of previously undisturbed natural habitats—forests, prairies, wetlands, and the like. Such destruction led directly or indirectly to the endangerment or extinction of many plant and animal species.
Some people wondered why anyone should care about losing species the human race did not even know existed. But scientists and others pointed out that a reduction of biodiversity—the natural variety of plants and animals—might threaten human health and prosperity. Many scientists argued that the global ecosphere—the interlocking system of life on earth—was intricate beyond present human understanding. What damaged one part of the ecosphere, they argued, might damage other parts, including those that humans depended on. The destruction of tropical rain forests, for example, which were being logged for lumber and burned to clear pasture land, doomed thousands of species per year. Some might have been useful in the search for medicines for the treatment of human disease, genes for genetically altered crop plants, or anything else worthwhile. Moreover, some environmentalists decried the destruction as morally unacceptable, regardless of its impact on humans. These critics contended that plants and animals had a right to exist— humans should not wantonly exterminate them.
Despite such arguments, however, environmentalist efforts to
preserve the earth’s biodiversity had only mixed success. In 1988, after
years of warnings about the dangers of destroying the world’s rain
forests, developing countries in Africa and Latin America continued to do
so. One environmental activist in Brazil, Chico Mendes, described the
process in his own country—shortly before ranchers who disliked his
interference killed him:
“In the last half
century Amazonia has never seen so many fires as in 1988. They are
burining everything. our airports were closed one week in 1987 because of
the smoke. This year they were closed one month for the same reason. When
you look down from the airplane, Amazonia is nothing but smoke. How it
In 1992, environmentalists convinced 167 nations attending a 1992 United Nations environmental conference in Brazil to sign a Convention on Biological Diversity. As one environmental group, the Worldwatch Institute, argued: “In an environmentally interdependent world, no country can separate its fate from that of the world as a whole.” But the terms of the treaty were vague, and enforcement appeared difficult if not impossible.
IDENTIFY and explain the significance of the following:
Main Idea What
negative effects did industrialization have on the environment?
Main Idea Why do scientists fear the loss of biodiversity?
Politics and Law
What efforts have environmentalists made to protect nature?
Writing to Persuade
Imagine that you are a farmer who raises crops on land claimed from
the rain forest. Write a short speech in which
you explain why you contribute to deforestation.
5. Synthesizing Why should people be concerned about the health of the planet?