General environment

• Amazing Environmental Organisation Web Directory
• Biogems
  
• Bluegreenearth.com
• Capitalism, Nature, Socialism
• Coalition for Environmentally Responsible Economies
  
• Corporate Watch
• Earth Action Centre (US)
• Earth Charter
  
• Earth Island Institute
• Earth Policy Institute
  
• Environmental Defence (US)
  
• Friends of the Earth, Australia
• The Ecologist
  
• Greenpeace International
  
• Grist
  
• Inform
  
• International Development Research Centre
  
• International Institute for Environment and Development
  
• Joel Kovel
• Museletter Richard Heinberg
  
• Oceana
• Rainforest Action Network
  
• Red Pepper
• Redefining Progress
  
• Resurgence
• Tellus Institute
  
• Bill Totten
• Union of Concerned Scientists
  
• Woods Hole Research Centre
  
• World Conservation Union
  
• World Resources Institute
  
• Worldwatch
  
• Worldwide Fund for Nature
  

Climate

• Chicago Climate Exchange
  
• Climate Neutral Network
  
• Pew Centre on Global Climate Change

Ecosocialism

• An ecosocialist manifesto

Energy

• Energy Bulletin
• No Nukes News
  

Ethical approaches

• Earth Ethics
• National Religious Partnership for the Environment (US)

Globalisation

• International Forum on Globalisation

Population

• Centre for Development and Population Activities
  
• People and the Planet
• Population Action International
  
• Population Council
  
• Population Reference Bureau
  
• UN Development Fund for Women
  
• UN Population Fund
  
• Women's Environmental and Development Organisation
• Women Watch (UN)