MOPITT AT NCAR
- Provides measurements of the global distributions of carbon monoxide (CO) and methane (CH4) in the troposphere. This is satellite data.
- http://www.eos.ucar.edu/mopitt/

IMPROVE (Interagency Monitoring of Protected Visual Environments)
- This section provides access to the raw and validated data products of aerosol, light scatter and light extinction in National Parks and Wilderness areas across the United States.
- http://vista.cira.colostate.edu/IMPROVE/Data/IMPROVE/improve_data.htm

Carbon Dioxide Information Analysis Center (CDIAC)
- Global-change data and information analysis for the US Department of Energy (DOE). Compiles and maintains extensive international data sets on atmospheric chemistry, particularly atmospheric concentrations of carbon dioxide, methane & other radiativel
- http://cdiac.esd.ornl.gov/

Mauna Loa Atmospheric CO2 data
- Time series record of carbon dioxide in the atmosphere.
- http://cdiac.esd.ornl.gov/ftp/maunaloa-co2/maunaloa.co2

British Atmospheric Data Centre (BADC)
- The Natural Environment Research Council (NERC) designated data centre for the Atmospheric Sciences in the United Kingdom.
- http://www.badc.rl.ac.uk/

AmeriFlux
- Long-term measurements of carbon dioxide, water vapor, and energy exchange from different ecosystems, which are integrated into consistent, quality assured, and fully documented data sets.
- http://public.ornl.gov/ameriflux/

ATMOS User Center
- Provides the European atmospheric satellite data user community with direct and easy access to measurements and derived data products from satellite based sensors.
- http://auc.dfd.dlr.de/