How did humans value and care for nature in the past? Why are we facing a biodiversity crisis now? What can we do about it?
Through much of European history, land and wilderness were viewed as resources that people could and should use for their own benefit. Most of the forests and Mediterranean ecosystems in Europe and its colonies were lost since they were turned into lumber, farms, and ranches.
At different times throughout the 1700s and 1800s though, colonial land managers realized that they needed to preserve some forests to prevent soil erosion, keep clean water flowing, and maintain food and lumber supplies. In Europe in the late 1800s, many species started declining in number or going extinct all together, which spurred the creation of various conservation groups and societies.
In the US, two areas were set aside for preservation as parks, even before the existence of national parks as a concept. Yosemite Valley became a state park in California in 1864 (now it is a National Park) and Yellowstone in Wyoming became the first national park in 1872, since no state government existed to manage it at the time.
In the late 1800s, Americans were starting to develop their views of nature and its relation to man. The main idea behind conservation in the United States is that wildlife belongs to the people—this concept is called the Public Trust Doctrine, and was formally instituted in a Supreme Court case in 1872.
Since wildlife belonged to the people, anyone could hunt, fish or harvest, which led to overexploitation of many game species (like the bison mentioned earlier). Hunters, worried their livelihoods were at stake, influenced the first game laws that restricted the methods and number of animals one person could take.
Leading the way in this regard was President Theodore Roosevelt, who created 230 million acres of protected land for wildlife conservation while he was president. Two 19th century philosophers also influence Americans' conservation thoughts: Ralph Waldo Emerson and Henry David Thoreau, who wrote about nature as a spiritual place. The writings of these two and John Muir, a wilderness explorer, pushed for preservation of natural areas with minimal human influence or modification.
After President Roosevelt put aside all that land, someone needed to be in charge of taking care of it. After all, Roosevelt was a capable man, but it would take more than one man to manage 230 million acres. Congress created the National Park Service in 1916 to look after the already protected areas and parks that would be created in the future.
Though there was some debate over what activities should be allowed on protected land, the conservation scene didn't really heat up again until the 1960s. In 1962, Rachel Carson published the book Silent Spring, blaming the pesticide DDT for killing large numbers of birds.
DDT, short for dichlorodiphenyltrichloroethane, is a chemical that was used to kill insects during and after World War II. While it was effective at killing agricultural pests, it affected other animals too. DDT goes through something called bioaccumulation, where it becomes more and more concentrated higher up in the food chain. When DDT meets birds of prey, it causes thinner eggshells, abnormal embryo development, and behavioral changes in adults. The combination of these changes led to big drops in population numbers for bald eagles, ospreys, and peregrine falcons in the 1950s.
DDT was banned in the US in 1972, around the same time other environmental laws were created. A big environmental movement in the 1960s led to creation of laws that protect air and water, and the Endangered Species Act.
Major environmental laws in the US have not changed much since the 1970s. There is currently a debate about whether carbon dioxide emissions should be regulated, since they contribute so much to climate change. These are exciting times we live in.