Fundamentals of Environmental Chemistry
http://manahans1.googlepages.com/
This site houses an array of resources for teaching environmental chemistry including:
1. An annotated PowerPoint presentation suitable for presentation as a general lecture to explain the basics of environmental chemistry to a general chemistry class or similar group can be downloaded from this site. This lecture emphasizes sustainability and covers environmental chemistry from the viewpoint of five environmental spheres: Hydrosphere, atmosphere, geosphere, biosphere, and anthrosphere.
2. An outline of a basic course in Environmental Chemistry based upon the book Fundamentals of Environmental Chemistry, 3rd ed., Taylor & Francis/CRC Press, 2009 by Stanley E. Manahan.
3. The book Green Chemistry and the Ten Commandments of Sustainability by Stanley Manahan and a complete set of PowerPoint presentations for this book can be downloaded from the Analytical Sciences Digital Library site free of charge.

The Habitable Planet: A Systems Approach to Environmental Science
http://www.learner.org/channel/courses/envsci/index.html
The Habitable Planet is a multimedia course for high school teachers and adult learners interested in studying environmental science. The web site provides a downloadable guide, online textbook, interactive teaching and learning tools, and video on demand. Each of the programs in the series includes two case studies featuring the work of top scientists in the field.
Units: Many Planets, One Earth; Atmosphere; Oceans; Ecosystems; Human Population Dynamics; Risk, Exposure, and Health; Agriculture; Water Resources; Biodiversity Decline; Energy Challenges; Atmospheric Pollution; Earth's Changing Climate; Looking Forward: Our Global Experiment 

National Repository of Online Courses: Environmental Science & AP Environmental Science
http://www.montereyinstitute.org/nroc/nrocdemos.html  
NROC is a library of online courses for students and faculty in higher education, high school, and advanced placement. (Note: Both the ES and AP ES courses contain the same content.)
Environmental Science
This course is designed to acquaint you with the physical, ecological, social, and political principles of environmental science. The scientific method is used to analyze and understand the inter-relationships between humans and the natural environment. The course shows how ecological realities and the material desires of humans often clash, leading to environmental degradation and pollution. The course covers the following topics: Earth's Systems, Human Population Dynamics, Natural Resources, Environmental Quality, Global Changes, and Environment and Society.
AP Environmental Science
This curriculum covers all of the material outlined by the College Board as necessary to prepare students to pass the AP Environmental Science exam. This course is designed to acquaint you with the physical, ecological, social, and political principles of environmental science. The scientific method is used to analyze and understand the inter-relationships between humans and the natural environment. The course shows how ecological realities and the material desires of humans often clash, leading to environmental degradation and pollution. The course covers the following topics: Earth's Systems, Human Population Dynamics, Natural Resources, Environmental Quality, Global Changes, and Environment and Society. 

Northwest Center for Sustainable Resources
http://www.ncsr.org/
NCSR is a national clearinghouse for natural resource curriculum materials used by college faculty and high school science teachers. The materials stress a science-based instruction approach to develop an accurate understanding of the principles of ecosystem-based resource management and sustainability and feature lecture-discussion, laboratory, and field-based teaching and learning approaches. Full courses and labs can be downloaded.
Instructional and Educational Materials: Aquatic Field and Lab Methods I & II; Environmental Ethics; Environmental Science I & II & III; Geographic Information System; Introduction to Mammalogy; Principles of Wildlife Conservation; Many More Topics

Fee-based Resources 

Web of School Science - Environmental Science Interactive
http://www.webschoolofscience.com/EnvScience.php
In this course are a series of interactive, inquiry-based environmental science simulations and exercises designed for college and AP high school environmental science courses.
Course Topics: Scientific method; Risk and uncertainty; Biodiversity; Evolutionary response; Human population dynamics; Conservation of endangered species; Interactions among species; Energy resources; Water resources; Waste management; Atmosphere and climate; Air pollution; Natural resource use and planning; Policy and decision making 

Aventa Learning: Environmental Science & AP Environmental Science
http://www.aventalearning.com/onlinecourses.html
Environmental Science
This course is an upper level science course. Environmental Science is a multidisciplinary field that draws from all the sciences in addition to other fields. This course will help students better understand the relationship between humans and the world in which we live. Environmental science applies the principles of pure sciences such as biology, chemistry, ecology, geology, and others.
AP Environmental Science
This course is designed to acquaint you with the physical, ecological, social, and political principles of environmental science. The scientific method is used to analyze and understand the interrelationships between humans and the natural environment. The course shows how ecological realities and the material desires of humans often clash, leading environmental degradation and pollution. The course consists of six chapters covering the following topics: Earth's Systems, Human Population Dynamics, Natural Resources, Environmental Quality, Global Changes and Environment and Society. Chapters are divided into several subsections, each of which contains text, animations, laboratory simulations and video presentations by experts. This course is one semester.