Humans are an integral part of ecosystems. Ecosystems provide a variety of benefits to people, including provisioning, regulating, cultural, and supporting services. Provisioning services are the products people ob- tain from ecosystems, such as food, fuel, fiber, fresh water, and genetic resources.

After completing this chapter, you will be able to:

1. Define environmental science and distinguish it from related fields such as environmental studies, ecology, and geography.

2. Explain the complexity of the universe through a hierarchical framework that includes consideration of Earth, life, and ecosystems at various scales.

3. Identify key principles of the ecosystem approach to conserving natural resources.

4. Describe how environmental stressors and disturbances can affect species and ecosystems.

5. Explain the history of human cultural evolution in terms of an increasing ability to cope with environmental constraints on the availability of natural resources and other aspects of economic development.

6. List at least three ways in which humans directly influence environmental conditions.

7. Identify four broad classes of environmental values.

8. Describe five important world views.

9. Understand the diverse issues of the environmental crisis by classifying them into three categories, and give several examples within each of them.