What is Environmental Science?

• Environmental science is the systematic study of our environment and our proper place in it.
• Environmental science is interdisciplinary, integrating natural sciences, social sciences, and humanities.
• Environmental science is mission-oriented and seeks knowledge about the natural world and our impacts on it.
• Living sustainably means meeting our own vital needs without compromising the ability of future generations to meet their own needs.
• The "ecological footprint" is a measure to compute the demands placed on nature by individuals and nations.
• The average world citizen has an ecological footprint of 2.3 global hectares, while the biologically productive space available is only 1.9 global hectares per person.
• The average resident of the United States lives at a consumption level that requires 9.6 ha of bioproductive land.
• Environment is the circumstances or conditions that surround an organism or group of organisms.
• Environment is the complex of social or cultural conditions that affect an individual or community.

History of Conservation

• Conservation history can be divided into four distinct stages: pragmatic resource conservation, moral and aesthetic nature preservation, pollution awareness, and global environmental citizenship.
• These stages are not mutually exclusive; elements of each persist in the modern environmental movement.

Pragmatic Resource Conservation

• This view emphasizes the importance of resource use for human benefit.
• Theodore Roosevelt and his chief conservation advisor, Gifford Pinchot, were key figures.
• Pinchot advocated for resource management on an honest, rational, and scientific basis.
• Resources should be used "for the greatest good, for the greatest number for the longest time."

Moral and Aesthetic Nature Preservation

• This view emphasizes the intrinsic value of nature, regardless of its usefulness to humans.
• John Muir, geologist, author, and first president of the Sierra Club, was a key figure.
• Aesthetic and spiritual values formed the core of Muir's philosophy of nature protection.
• This outlook has been called biocentric preservation because it emphasizes the fundamental right of other organisms to exist and to pursue their own interests.

Modern Environmentalism

• Rachel Carson's book Silent Spring (1962) awakened the public to the threats of pollution and toxic chemicals.
• The movement she engendered might be called environmentalism because its concerns are extended to include both environmental resources and pollution.
• Activist David Brower and scientist Barry Commoner were among the pioneers of this movement.

Global Environmentalism

• Photographs of the earth from space provide a powerful icon for global environmentalism.
• Roger Hooke estimates that current human earth-moving activities now rival those of natural geological forces.
• Protecting our environment has become an international cause and it will take international cooperation to bring about many necessary changes.
• The links between poverty, injustice, oppression, and exploitation of humans and our environment have begun to be appreciated.

Current Conditions

• The opening story of the chapter illustrates, questions remain about whether resources and ecological services can support that many humans.
• At least 1.1 billion people lack access to safe drinking water, and twice that many don't have modern sanitation.
• About 40 percent of the world population lives in countries where water demands now exceed supplies.
• Soil scientists report that about two-thirds of all agricultural lands show signs of degradation.
• Fossil fuels presently provide around 80 percent of the energy used in industrialized countries.

Environmental Problems - Frog Deformities

• Frog abnormalities include missing or extra limbs and internal problems, affecting many species.
• Suggested causes of amphibian malformations are chemical contamination, ultraviolet (UV) solar radiation, and parasite infection.
• Currently, the leading candidate for amphibian malformalities seems to be parasite infections with cysts of a invasive trematode fluke named Ribeiroia ondatrae.
• Extra nutrients stimulate algal blooms and aquatic vegetation growth that provide food for snails, the intermediate host for the parasite.

Environmental Dilemmas - Climate Change

• Burning fossil fuels, making cement, cultivating rice paddies, clearing forests, and other human activities release carbon dioxide and other so-called "greenhouse gases".
• Climatologists warn that mean global temperatures will probably warm 1.5° to 6°C (2.7-11°F).
• Global climate change already is affecting a wide variety of biological species and melting alpine glaciers and snowfields could threaten water supplies.