Links to Public Data Sites:

GIOVANNI - access to NASA satellite remote sensing data
NDACC - Network for the Detection of Atmospheric Composition Change
TCCONTotal Carbon Column Observing Network
MOPITT - Satellite CO measurements
World Data Centre for Greenhouse Gases
World Data Centre for Ozone and UV Radiation
World Data Centre for Remote Sensing - satellite-based data sets
World Data System - new site collating World Data
Global Carbon Project - latest research on global carbon cycling