Carbon Dioxide Information Analysis Center (CDIAC) (Popularity: )
http://cdiac.esd.ornl.gov/ 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 & ...
EOS-WEBSTER (Popularity: )
http://eos-webster.sr.unh.edu/ Digital library of free, customized earth science data from The University of New Hampshire. Data can be FTPd or mailed on a customized CD.
National Snow and Ice Data Center (Popularity: )
http://www.nsidc.org The National Snow and Ice Data Center (NSIDC) is part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder. NSIDC supports research into ...