- Climate Headlines – a service of the UNFCCC (International)
- Environmental and Energy Study Institute
- U.S. EPA Global Warming Site
- U.S. Global Change Research Information Office
- Global Warming International Center
- International Council for Local Environmental Initiatives
- Intergovernmental Panel on Climate Change
- The Pew Center
- SafeClimate
- Weathervane
- U.S. Global Change Research Program
Other Registries
- New Hampshire GHG Summary
- Wisconsin Voluntary Emission Reductions Registry Advisory Committee
- Voluntary Reporting of GHG Program
- Environmental Resources Trust, Inc.
- Voluntary Challenge & Registry, Inc.
Emissions Trading
- Natsource
- Chicago Climate Exchange
- CO2e.com
- International Emissions Trading Association
- The Carbon Trader
General
- Climate Neutral Network
- The Climate Trust
- The Energy Foundation
- Environmental Defense
- California Energy Commission
- GHG Protocol Initiative
- Natural Resources Defense Council
- United Nations Environment Programme
- World Business Council for Sustainable Development
- World Resources Institute
