Save Our Environment
   
Save Our Environment Action Center is a collaborative effort of influential environmental organizations that deal in increasing public awareness and activism on important environmental issues. It strives to protect air, water, land, forests, ocean, wildlife and planet's climate through its activities.
http://www.saveourenvironment.org/

Defenders of Wildlife
  
Defenders of Wildlife protect native wild animals and plants. It focuses upon preventing the extinction of species and biological diversity, habitat alteration and destruction. It programs and implements protection of ecosystems and the natural habitats.
http://www.defenders.org/
  

Earthjustice
 
Earthjustice is a non-profit public interest law firm. It works through the courts to safeguard public lands, national forests, parks, and wilderness areas; to reduce air and water pollution; to prevent toxic contamination; and to preserve endangered species and wildlife habitat by asking for strengthening and stricter enforcement of environment laws.
http://www.earthjustice.org/
 

Union of Concerned Scientists
  
The Union of Concerned Scientists is a nonprofit partnership of scientists and citizens combining scientific analysis, policy development and effective citizen advocacy to achieve practical environmental solutions
http://www.ucsusa.org/
   

Physicians for Social Responsibility
  
Physicians for Social Responsibility combines active and concerned citizens with the physicians, health professionals to promote public policies, awareness for protection of human health from nuclear war, biological weapons, global environmental degradation.
http://www.psr.org/