Greenpeace. International NGO with a goal to "ensure the ability of the Earth to nurture life in all its diversity."
Center for Environmental Research and Conservation. Sustainability think tank based at Columbia University. See their list of publications.
Earth Island Institute. Founded by David R. Brower, acts as an environmental umbrella organization, providing people and groups the capability to develop initiatives through professional services.
Environmental Defense Fund. Works on global warming,ecosystem restoration, oceans, and human health.
Fauna and Flora International.Works to conserve threatened species and ecosystems worldwide into account human needs.
Nature Friends International. Global environmental umbrella organization.
Global Footprint Network. International think tank that provides ecological footprint accounting tools to drive policy decisions in a resource-constrained world
International Union for Conservation of Nature. Union composed of government and civil society organizations to provide the knowledge and tools that enable human progress, economic development and nature conservation to take place together.
Nature Conservancy. Conservation organization working to protect ecologically important lands and waters for nature and people.
Natural Resources Defense Council. International environmental advocacy group with a staff of hundreds of lawyers, scientists and policy experts.
Wetlands International. Global not-for-profit organization dedicated to the conservation and restoration of wetlands.
World Agroforestry Centre. Generates knowledge about the benefits of agroforestry to develop policy and practices for improved livelihoods and environmental benefits.
Worldwatch Institute. Works for universal access to renewable energy and nutritious food, expansion of environmentally sound jobs and development, transformation from consumerism to sustainability.
World Wildlife Fund. International Conservation Organization - see also the International Secretariat based in Geneva.