These web sites deal with environmental issues for the planet Earth.
These topics matter to anyone who lives here.
EnviroWeb A gold mine of environmental information and a gateway to numerous other sites. Its motto: "Communicate globally, act locally." 
Sierra Club The environmental organization founded by John Muir.
Greenpeace Like the organization itself, the web page presents the right mix of substance and showmanship. Files and press releases on environmental issues including whaling, the climate, Alaskan oil spill, etc., with dramatic graphics of Greenpeace in action. 
Union of Concerned Scientists A forum for concerns about the military, and about the environment.
University of Northern Texas A very good site from the center for environmental philosophy with links to numerous other sites and programs. The Journal, Environmental Ethics is here and a searchable Bibliography. 
The International Society for Environmental Ethics Another site with a searchable bibliography
The Harvard University site for Environmental Ethics Harvard hosts a huge collection of links to Environmental Ethics