Most organizations listed in this area are concerned with a wide range of environmental topics. Single-focus organizations are found under the appropriate topical headings.

Some listings are actually links to categories elsewhere in the directory. This category is for scientifically-oriented organizations. Environmental advocacy groups are listed in Society:Issues:Environment:Organizations.

Listed as Subcategories:

"Governmental" includes national government agencies and international intergovernmental agencies (such as United Nations organizations).

"Industry Groups" lists environmental sites maintained by private corporations or industry consortia.

"Professional Associations" are organizations of professionals engaged in various environmental fields.

"Research Institutes" are operated by universities, governments, foundations, and NGOs. They are engaged primarily in acquisition and dissemination of scientific and technical knowledge about the environment or its protection.

Most websites listed in this category may also be listed once in the Regional category for the country, state, province, region, or other geographic area where they are active.
This category includes national government and international intergovernmental agencies. Categories devoted to individual agencies may be found under the appropriate Regional/ category for the country represented.
Most websites listed in this category may also be listed once in the Regional category for the country, state, province, region, or other geographic area where they are active.
Professional associations in environmental science fields.
This category is primarily for professional associations that encompass broad areas of environmental science or do not fit elsewhere. Associations for specific areas of environmental science should be listed in the appropriate "@category."