Wildlife

The early-to mid-twentieth century was marked by an increased scientific understanding of wildlife and an increased willingness on the part of nations to protect it. The International Union for the Protection of Nature (now the World Conservation Union) was established in 1948 and gave birth shortly thereafter to the World Wildlife Fund. These and other global organizations, such as the United Nations, and conventions, such as the Convention Concerning the Protection of World Cultural and Natural Heritage (1972), were dedicated to protecting wildlife through a variety of strategies. These included moratoriums on trade in endangered species and the creation of reserves, such as those designated as World Natural Heritage Sites.

Despite such efforts, the continuing humanization of the planet made the long-term survival prospects for wildlife increasingly uncertain. As the twentieth century ended, the biological sciences conclusively established the reality of an anthropogenic mass extinction of terrestrial flora and fauna. Estimates of human-caused extinction rates ranged from a low of one hundred to a high of one thousand times greater than natural rates. Humankind's increasing population and subsequent levels of economic demand led to rapid development of the few remaining areas, such as Amazonia, that were primary habitats for wildlife. Patterns of human settlement in developed nations, including sprawl, urbanization, and the fragmentation of habitat, increasingly impacted remnant populations of wild plants and animals. Less direct impacts on wildlife were the consequence of the increase in global temperature, predicted by the Intergovernmental Panel on Climate Change to increase by 5 to 10 degrees Fahrenheit over the twenty-first century. Given such dramatic increase, the possibility of retreat by heat sensitive species appeared doubtful.

Progress in scientific understanding was paralleled by ethical advance. The pioneering work of Thoreau and Muir was followed in the twentieth century by a variety of ecological ethics that charged humanity with obligations to conserve wild places and things, and to restore those species, such as the wolf, that had been thoughtlessly endangered. These ranged from the secular, such Aldo Leopold's (1887–1948) land ethic, A Sand County Almanac (1949), to the religious caring for creation movement that followed Lynn White, Jr.'s charge in a 1967 issue of Science magazine that Jews and Christians were to blame for ecological crisis.

Rachel Carson's Silent Spring (1961), which focused on the consequences for avian species of the toxic chemicals used in a war against nature, marked the point where the environmental movement became a mass phenomenon. Membership in organizations dedicated to the conservation, preservation, and restoration of wildlife soared. As public interest increased in America, legislative action, such as the passage of the Wilderness Act (1964), the National Environmental Policy Act (1969), and the Endangered Species Act (1973), followed. Such laws, and similar ones passed in other nations, are the cornerstone of wildlife protection.